ductless gland vs gland

ductless gland and gland both are nouns.

Word	Noun	Adjective	Verb	Adverb
ductless gland	Yes	No	No	No
gland	Yes	No	No	No

As nouns, gland is a hypernym of ductless gland; that is, gland is a word with a broader meaning than ductless gland:

ductless gland: any of the glands of the endocrine system that secrete hormones directly into the bloodstream
gland: any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream

Other hypernyms of ductless gland include secreter, secretor, secretory organ.

ductless gland (noun)	gland (noun)
any of the glands of the endocrine system that secrete hormones directly into the bloodstream	any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream