artichoke heart vs veggie

artichoke heart and veggie both are nouns.

Word	Noun	Adjective	Verb	Adverb
artichoke heart	Yes	No	No	No
veggie	Yes	No	No	No

As nouns, veggie is a hypernym of artichoke heart; that is, veggie is a word with a broader meaning than artichoke heart:

artichoke heart: the tender fleshy center of the immature artichoke flower
veggie: edible seeds or roots or stems or leaves or bulbs or tubers or nonsweet fruits of any of numerous herbaceous plant

Other hypernyms of artichoke heart include veg, vegetable.

artichoke heart (noun)	veggie (noun)
the tender fleshy center of the immature artichoke flower	edible seeds or roots or stems or leaves or bulbs or tubers or nonsweet fruits of any of numerous herbaceous plant