acetyl radical vs acyl group

acetyl radical and acyl group both are nouns.

Word	Noun	Adjective	Verb	Adverb
acetyl radical	Yes	No	No	No
acyl group	Yes	No	No	No

As nouns, acyl group is a hypernym of acetyl radical; that is, acyl group is a word with a broader meaning than acetyl radical:

acetyl radical: the organic group of acetic acid (CH3CO-)
acyl group: any group or radical of the form RCO- where R is an organic group

Other hypernyms of acetyl radical include acyl.

acetyl radical (noun)	acyl group (noun)
the organic group of acetic acid (CH3CO-)	any group or radical of the form RCO- where R is an organic group