dace

noun, plural (especially collectively) dace, (especially referring to two or more kinds or species) dac·es.

1. a small, freshwater cyprinoid fish, Leuciscus leuciscus, of Europe, having a stout, fusiform body.
2. any of several similar or related fishes of the U.S.

noun plural dace or daces

1. a European freshwater cyprinid fish, Leuciscus leuciscus, with a slender bluish-green body
2. any of various similar fishes

n.

small, freshwater fish, early 15c., from Old French darz, nominative or plural of dart “dart” (see dart). So called for its movements. Another theory traces it to a Medieval Latin darsus, said to be of Gaulish origin.