Root Words | Definition, List & Examples

Sentence and word structure updated on  March 22, 2024 5 min read

A root word is the most basic part of a word and does not have any affixes (i.e., prefixes or suffixes) attached. A root word is the fundamental unit of a word and forms the basis for a word family, or all the words that can be created using the root word.

A root word can be built on using prefixes (e.g., “pre-”, “de-,” “anti-”) and suffixes (e.g., “-able”/“-ible,” “-tion,” “-ly”). Adding prefixes or suffixes to root words creates new words.

For example, the word “proportionate” is made up of these components:


root word


pro portion ate

A root word like “portion” is the basis of a word family that includes many other words, such as “improportion,” “disproportional,” and “proportionality.” Word families contain words that share similar spelling as well as meaning.

What is a root word?

A root word is the fundamental unit of a word. Importantly, while some root words can function as standalone words, others must be joined with affixes to form a complete word.

Many English words derive from Latin and Greek root words. For example, the Latin “vis” (“see”) is the root of “invisible” and “visual.” However, like most Latin and Greek root words, “vis” cannot stand on its own as a meaningful word.

In contrast, other root words do not require a prefix or suffix to be a complete word that makes sense within a sentence. For example, a word like “potent” functions as both a standalone word meaning “powerful” and as the root for other words, including “potential,” “impotent,” and “potentiate.”

Understanding and recognizing root words can enable you to break down new or longer words. This is especially useful when you encounter long or specialized words. In fact, many root words that come from Latin and Greek are used for mathematical and scientific terms. Examples of this include “equ” (Latin for “equal”) and “astro” (from the Greek “astron,” meaning “star”).

Affixes are a type of morpheme, or a grammatically meaningful unit of language. Affixes comprise both prefixes and suffixes, and they must be combined with root words; they cannot stand on their own.

  • Prefixes are affixes that are placed at the beginning of a word. Common prefixes include “re-” (“again”), “anti-” (“against”), “semi-” (“partial”), “non-” (“lack of”), “sub-” (“under”), and “ex-” (“outside”).
  • Suffixes are affixes that are placed at the end of a word. Common suffixes include “-dom” (“domain,” “condition”), “-able”/“-ible” (“capable of”), “-ion” (“process”), and “-ful” (“full of”).

Example root words

Root words can be used independently or may need to be combined with a prefix (i.e., letters at the beginning), a suffix (i.e., letters at the end), or another root word (e.g., “-logue”) to form a standalone word.

Root word



act to do active, reaction, actor
centr/o/i center central, centripetal, epicenter
cur attention curate, curious, manicure
domin master domain, domineer, dominion
form shape formative, inform, reform
gram writing grammar, telegram, monogram
hap luck happy, happen, mishap
note comment upon connote, notification, notorious
odor smell odorous, deodorant, odorize
retro backward retrospective, retrograde, retroactive
use take or hold user, useless, misuse

Root words vs base words

Base words, like root words, can be combined with other morphemes (or units of words) to create more complex words. Although root words and base words are similar concepts, they have a key difference: whereas all base words can occur on their own as meaningful words, not all root words can be used as standalone words.

For example, the base word “friend” is perfectly grammatical on its own, or it can be combined with affixes to form new words (e.g., “friendship,” “friendly,” or the neologism “unfriend”). At the same time, the Greek root word “cosmo” (meaning “order” or “world”) must be joined with other morphemes to create usable words like “cosmopolitan,” “cosmonaut,” and “cosmetics.”

Some base words are also root words, but not all root words are base words because not all root words can stand on their own. “Sum” (“highest”) is both a base word and a root word: it can be used on its own in a sentence, or it can be linked with suffixes like “-ary” (“summary”) or “-mit” (“summit”) to form new words.

Latin root words (free downloadable list)

The list below presents common Latin root words along with their meanings and examples. Most Latin root words cannot be used as words on their own.

You can download this list using the links below.




anim(a) breath or soul animosity, animus, animalistic
aqua water aqueous, aqueduct, aquaplane
aud to hear/listen audacity, audience, audit
bene good benevolent, beneficial, benedict
brev short abridge, abbreviate, brief
cand/cend to glow/shine candle, candor, candidacy
carn meat or flesh carnal, incarnate, carnival
cred to believe/trust credo, credibility, credence
delicia pleasure delicious, delight, delicacy
dict/dic to say dictate, dictum, edict
doc to teach doctor, docent, indoctrinate
duce/duct to lead ductile, induct, production
hospit host, guest host, hostile, hospitalize
jur/jus law/right/oath justify, jurisprudence, judge
liber free liberate, liberal, liberty
luc/lum brightness/clarity illuminate, luminous, Lucifer
magn great/large magnify, magnate, magnoscope
manu hand manufacture, manual, maneuver
pac peace peace, pacify, pact
port to carry portable, porter, opportunity
scrib/script to write circumscribe, description, scribble
sens to feel sensitive, sentient, sensible
terr earth inter, exterior, terrace
vac empty vacuous, vacation, vacant
vis/vid to see visual, view, vision

Greek root words (free downloadable list)

The list below presents common Greek root words along with their meanings and examples. Most Greek root words cannot be used as words on their own.

You can download this list using the links below.




aero air aerosol, anaerobic, air
anthrop human Anthropocene, anthropologist, anthropomorphism
astro/aster star astrology, astronomer, astrophysics
auto self automobile, automaton, automation
bio life biomedicine, biological, bionic
chrome color chromatography, polychrome, monochromatic
chrono time chronology, chronometer, anachronism
cosm(o) world/universe cosmic, cosmonaut, cosmetics
dyn power dynasty, dynamism, dynamo
hemo blood hemophilia, hemoglobin, hemorrhage
gnos know ignorant, incognito, cognition
graph write graphic, graph, paragraph
hydr water hydroelectric, hydraulics, hydrant
logy study philology, tautology, gastroenterology
mania frenzy manic, maniac, kleptomania
metron/meter measure symmetrical, metronome, speedometer
monos alone monocle, monk, monastery
paleo old paleography, paleontologist, paleoclimatology
path experience pathos, pathology, sociopath
phil to love philanthropy, cinephile, philosophy
phon sound/voice polyphonic, phoneme, phonograph
photo light photogenic, photosynthesis, photovoltaic
phyto growth phytoplankton, neophyte, phytotoxin
psych soul/spirit psychosis, psychopath, psyche
schem shape/manner schema, ischemia, scheming
therm heat thermal, thermodynamics, hyperthermia

Base words

Base words can either be used on their own or can be expanded to create new words.

Base word

Derived word

act activate
blood bloodless
care carefree
day today
do undone
head ahead
home homebound
hope hopeful
join joint
life lifeless
love lovable
nice nicety
out outing
pilot autopilot
place displacement
play downplay
red reddish
spell spellbound
worth worthless

Recommended articles

Do you want to know more about verbs, commonly confused words, or other language topics? Check out some of our other language articles full of examples and quizzes.


Commonly confused words


Past participle

Conversate vs converse

Logical fallacy

Prepositional phrase

Worse vs worst

Ecological fallacy

Split infinitive

Row vs column

Base rate fallacy

Verb phrase

Your vs you're

Appeal to emotion fallacy

Dangling participle

Has vs have

False cause fallacy

Frequently asked questions about root words

How can I identify a root word?

To break down a word and identify the root, it is helpful to first identify any affixes attached to the word. Prefixes and suffixes often modify root words, so removing these can reveal the root word and help you unlock the word’s meaning.

For example, “predated” has the prefix “pre-” (“before”) and the suffix “-ed,” which is used here to indicate the past tense. Removing the prefix and the suffix gives us the root word “datus,” or the past participle of “dare,” “to give,” in Latin.

What is the difference between a root word and a base word?

Base words can be used as independent words in a sentence (e.g., “super”), or they can be joined with other morphemes (units of words) to create new words (e.g., “superior,” “superintendent”).

In contrast, some root words can be used as independent words (e.g., “ever”), but other root words require affixes to form meaningful, standalone words (e.g., “struct”).

What are word families?

Root words form the basis of word families, or groups of all the words derived from a given root.

Word families include all the inflections and derivations of a given root word. However, because language evolves over time, some words in a word family might have very different meanings, even if they share the same etymological root.


Alexandra Rongione

Alexandra has a master’s degree in literature and cultural studies. She has taught English as a foreign language for a range of levels and ages and has also worked as a literacy tutor.

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