small marine fish, early 14c., from Old French gournart (13c.), formed by metathesis of gronir, from Latin grunire "to grunt." The fish so called for the sound it makes when pulled from the water. Compare grunt (n.), grunion.
1550s, from grunt (v.); as a type of fish, from 1713, so called from the noise they make when hauled from the water; meaning "infantry soldier" emerged in U.S. military slang during Vietnam War (first recorded in print 1969); used since 1900 of various low-level workers. Grunt work first recorded 1977.
type of Pacific fish, 1901, from American Spanish gruñon "grunting fish," from grunir "to grunt," from Latin grunnire, from Greek gryzein "to grunt," from gry "a grunt," imitative. Compare the unrelated American fish called the grunt, "so called from the noise they make when taken."
<a href="https://www.etymonline.com/word/gurnard">Etymology of gurnard by etymonline</a>
Harper, D. (n.d.). Etymology of gurnard. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/gurnard