ductulus vs duct

ductulus and duct both are nouns.

Word	Noun	Adjective	Verb	Adverb
ductulus	Yes	No	No	No
duct	Yes	No	No	No

As nouns, duct is a hypernym of ductulus; that is, duct is a word with a broader meaning than ductulus:

ductulus: a very small duct
duct: a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance

Other hypernyms of ductulus include canal, channel, epithelial duct.

ductulus (noun)	duct (noun)
a very small duct	an enclosed conduit for a fluid
	a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance
	a continuous tube formed by a row of elongated cells lacking intervening end walls