boastful vs cock-a-hoop

boastful and cock-a-hoop both are adjectives.

Word	Noun	Adjective	Verb	Adverb
boastful	No	Yes	No	No
cock-a-hoop	No	Yes	No	No

As adjectives, boastful and cock-a-hoop are synonyms defined as:

Other synonyms of boastful include big, braggart, bragging, braggy, crowing, self-aggrandising, self-aggrandizing.

boastful (adjective)	cock-a-hoop (adjective)
exhibiting self-importance	exhibiting self-importance