troy unit vs ounce

troy unit and ounce both are nouns.

Word	Noun	Adjective	Verb	Adverb
troy unit	Yes	No	No	No
ounce	Yes	No	No	No

As nouns, ounce is a hyponym of troy unit; that is, ounce is a word with a more specific, narrower meaning than troy unit:

troy unit: any of the unit of the troy system of weights
ounce: a unit of apothecary weight equal to 480 grains or one twelfth of a troy pound

Other hyponyms of troy unit include grain, pennyweight, apothecaries' ounce, troy ounce, apothecaries' pound, troy pound.

troy unit (noun)	ounce (noun)
any of the unit of the troy system of weights	large feline of upland central Asia having long thick whitish fur
	a unit of weight equal to one sixteenth of a pound or 16 drams or 28.349 grams
	a unit of apothecary weight equal to 480 grains or one twelfth of a troy pound