karat vs carat

karat and carat both are nouns.

Word	Noun	Adjective	Verb	Adverb
karat	Yes	No	No	No
carat	Yes	No	No	No

As nouns, karat and carat are synonyms defined as:

karat and carat: the unit of measurement for the proportion of gold in an alloy; 18-karat gold is 75% gold; 24-karat gold is pure gold

Other synonyms of karat include kt.

karat (noun)	carat (noun)
the unit of measurement for the proportion of gold in an alloy; 18-karat gold is 75% gold; 24-karat gold is pure gold	a unit of weight for precious stones = 200 mg
	the unit of measurement for the proportion of gold in an alloy; 18-karat gold is 75% gold; 24-karat gold is pure gold