noun
carat
A measure of gold purity expressed in twenty-fourths.
The British catalog described the ring as eighteen carat gold.
Etymology
Greek keration named a carob pod, whose seeds were used as weights. The weight term also developed a proportional use for gold, expressing the pure-gold share out of twenty-four parts.
More examples
- In that hallmark guide, carat indicates gold purity.
- The imported label used carat where an American label would use karat.
- Twenty-four carat gold is the highest purity on that scale.
Forms
carat · carats
Similar words
- karat
- Karat is the standard American spelling for gold purity; carat is chiefly British for this sense.