ounce vs troy ounce

ounce and troy ounce both are nouns.

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

As nouns, ounce and troy ounce are synonyms defined as:

ounce and troy ounce: a unit of apothecary weight equal to 480 grains or one twelfth of a troy pound

Other synonyms of ounce include apothecaries' ounce.

ounce (noun)	troy ounce (noun)
large feline of upland central Asia having long thick whitish fur	a unit of apothecary weight equal to 480 grains or one twelfth of a troy pound
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