omelette vs firm omelet

omelette and firm omelet both are nouns.

Word	Noun	Adjective	Verb	Adverb
omelette	Yes	No	No	No
firm omelet	Yes	No	No	No

As nouns, firm omelet is a hyponym of omelette; that is, firm omelet is a word with a more specific, narrower meaning than omelette:

omelette: beaten eggs or an egg mixture cooked until just set; may be folded around e.g. ham or cheese or jelly
firm omelet: eggs beaten with milk or cream and cooked until set

Other hyponyms of omelette include fluffy omelet, egg foo yong, egg fu yung.

omelette (noun)	firm omelet (noun)
beaten eggs or an egg mixture cooked until just set; may be folded around e.g. ham or cheese or jelly	eggs beaten with milk or cream and cooked until set