em ‧ e ‧ rald /ˈem ə rəld/ BrE AmE noun
[ Date: 1200-1300 ; Language: Old French ; Origin: emeraude , from Latin smaragdus ]
1 . [countable] a valuable bright green stone that is often used in jewellery
2 . [uncountable] a bright green colour
—emerald adjective