bullace vs plum tree

bullace and plum tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
bullace	Yes	No	No	No
plum tree	Yes	No	No	No

As nouns, plum tree is a hypernym of bullace; that is, plum tree is a word with a broader meaning than bullace:

bullace: small wild or half-domesticated Eurasian plum bearing small ovoid fruit in clusters
plum tree: any of several trees producing edible oval fruit having a smooth skin and a single hard stone

Other hypernyms of bullace include plum.

bullace (noun)	plum tree (noun)
small wild or half-domesticated Eurasian plum bearing small ovoid fruit in clusters	any of several trees producing edible oval fruit having a smooth skin and a single hard stone