criticism vs brickbat

criticism and brickbat both are nouns.

Word	Noun	Adjective	Verb	Adverb
criticism	Yes	No	No	No
brickbat	Yes	No	No	No

As nouns, brickbat is a hyponym of criticism; that is, brickbat is a word with a more specific, narrower meaning than criticism:

criticism (noun)	brickbat (noun)
a serious examination and judgment of something	blunt criticism
disapproval expressed by pointing out faults or shortcomings	a fragment of brick used as a weapon
a written evaluation of a work of literature