hydroxyl vs hydroxyl radical

hydroxyl and hydroxyl radical both are nouns.

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

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

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

Other synonyms of hydroxyl include hydroxyl group.

hydroxyl (noun)	hydroxyl radical (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