What does above reproach mean?

If something is above reproach, it means that there is no reason to criticize it, especially in terms of moral correctness (e.g., “A judge’s conduct must be above reproach,” “The journal stated that the peer-reviewed article is above reproach and will not be retracted”).

QuillBot’s Paraphraser will help you to find alternatives for “above reproach” that fit that context of your text.