hair ball vs trichobezoar

hair ball and trichobezoar both are nouns.

Word	Noun	Adjective	Verb	Adverb
hair ball	Yes	No	No	No
trichobezoar	Yes	No	No	No

As nouns, hair ball and trichobezoar are synonyms defined as:

hair ball and trichobezoar: a compact mass of hair that forms in the alimentary canal (especially in the stomach of animals as a result of licking fur)

Other synonyms of hair ball include hairball.

hair ball (noun)	trichobezoar (noun)
a compact mass of hair that forms in the alimentary canal (especially in the stomach of animals as a result of licking fur)	a compact mass of hair that forms in the alimentary canal (especially in the stomach of animals as a result of licking fur)