acyl groups

Groups formed by removing one or more hydroxy groups from oxoacids that have the general structure RkE(=O)l(OH)m (l ≠ 0), and replacement analogues of such acyl groups. In organic chemistry an unspecified acyl group is commonly a carboxylic acyl group. E.g.
A00123
Source:
PAC, 1995, 67, 1307 (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1311