Ac·yl n. A organic radical having the general formula RCO, derived from the removal of a hydroxyl group from an organic acid. acyl 1. [more]Acyl group - Community and Resources
Noun 1. any group or radical of the form RCO- where R is an organic group; "an example of the acyl group is the acetyl group" (synonym) acyl (hypernym) group, radical, chemical group (hyponym) acetyl, acetyl group, acetyl radical, ethanoyl group, ethanoyl radical