emerald

Concise Oxford English Dictionary © 2008 Oxford University Press:
emerald/ˈemərəld/

▶noun

• 1 a bright green precious stone consisting of a chromium-rich variety of beryl.

• 2 (also emerald green) a bright green colour.

• 3 (also emerald moth) a slender-bodied green moth. [Geometra papilionaria (large emerald) and other species.]

– phrases
the Emerald Isle Ireland.

– origin ME: from OFr. e(s)meraud, ult. via L. from Gk (s)maragdos, via Prakrit from Semitic (cf. Heb. bāreqeṯ, from bāraq ‘flash, sparkle’).