Root Words | Definition, List & Examples
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:
| pro | portion | ate |
|---|---|---|
| prefix | root word | suffix |
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 | Meaning | Examples |
|---|---|---|
| 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.
| Root | Meaning | Examples |
|---|---|---|
| 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.
| Root | Meaning | Examples |
|---|---|---|
| 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 |
|---|---|
| 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 |
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 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.
