egg foo yong vs omelet

egg foo yong and omelet both are nouns.

Word	Noun	Adjective	Verb	Adverb
egg foo yong	Yes	No	No	No
omelet	Yes	No	No	No

As nouns, omelet is a hypernym of egg foo yong; that is, omelet is a word with a broader meaning than egg foo yong:

egg foo yong: omelet containing onions and celery and chopped meat or fish
omelet: beaten eggs or an egg mixture cooked until just set; may be folded around e.g. ham or cheese or jelly

Other hypernyms of egg foo yong include omelette.

egg foo yong (noun)	omelet (noun)
omelet containing onions and celery and chopped meat or fish	beaten eggs or an egg mixture cooked until just set; may be folded around e.g. ham or cheese or jelly