hydroxyl vs hydroxyl group

hydroxyl and hydroxyl group both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydroxyl	Yes	No	No	No
hydroxyl group	Yes	No	No	No

As nouns, hydroxyl and hydroxyl group are synonyms defined as:

hydroxyl and hydroxyl group: the monovalent group -OH in such compounds as bases and some acids and alcohols

Other synonyms of hydroxyl include hydroxyl radical.

hydroxyl (noun)	hydroxyl group (noun)
the monovalent group -OH in such compounds as bases and some acids and alcohols	the monovalent group -OH in such compounds as bases and some acids and alcohols