bigheaded vs too big for one's breeches

bigheaded and too big for one's breeches both are adjectives.

Word	Noun	Adjective	Verb	Adverb
bigheaded	No	Yes	No	No
too big for one's breeches	No	Yes	No	No

As adjectives, bigheaded and too big for one's breeches are synonyms defined as:

bigheaded and too big for one's breeches: (used colloquially) overly conceited or arrogant

Other synonyms of bigheaded include persnickety, snooty, snot-nosed, snotty, stuck-up, uppish.

bigheaded (adjective)	too big for one's breeches (adjective)
(used colloquially) overly conceited or arrogant	(used colloquially) overly conceited or arrogant