1. A functional group or radical derived from an organic acid by removal of the hydroxyl group, typically represented as RCO- where R is an alkyl or aryl group.
Usage: chemistry; technical term

Examples

• The acyl group is a key structural feature in many organic compounds.
• Acetyl is the simplest acyl group, derived from acetic acid.
• Acyl chlorides are commonly used in organic synthesis.
• The acyl radical plays an important role in free-radical reactions.
• Benzoyl is an acyl group derived from benzoic acid.