tear sac vs vesicle

tear sac and vesicle both are nouns.

Word	Noun	Adjective	Verb	Adverb
tear sac	Yes	No	No	No
vesicle	Yes	No	No	No

As nouns, vesicle is a hypernym of tear sac; that is, vesicle is a word with a broader meaning than tear sac:

tear sac: either of the two dilated ends of the lacrimal ducts at the nasal ends of the eyes that fill with tears secreted by the lacrimal glands
vesicle: a small anatomically normal sac or bladderlike structure (especially one containing fluid)

Other hypernyms of tear sac include cyst.

tear sac (noun)	vesicle (noun)
either of the two dilated ends of the lacrimal ducts at the nasal ends of the eyes that fill with tears secreted by the lacrimal glands	a small anatomically normal sac or bladderlike structure (especially one containing fluid)