wych elm vs elm

wych elm and elm both are nouns.

Word	Noun	Adjective	Verb	Adverb
wych elm	Yes	No	No	No
elm	Yes	No	No	No

As nouns, elm is a hypernym of wych elm; that is, elm is a word with a broader meaning than wych elm:

wych elm: Eurasian elm often planted as a shade tree
elm: any of various trees of the genus Ulmus: important timber or shade trees

Other hypernyms of wych elm include elm tree.

wych elm (noun)	elm (noun)
Eurasian elm often planted as a shade tree	any of various trees of the genus Ulmus: important timber or shade trees
	hard tough wood of an elm tree; used for e.g. implements and furniture