/muy"sid/ , n.
1. any member of the malacostracan order Mysidacea, the opossum shrimps, esp. of the genus Mysis.
adj.
2. of or pertaining to such shrimps.
[ 1940-45; Mysidae a family of the order, equiv. to Mys ( is ) the type genus ( mýsis shutting ( mý ( ein ) to shut (the mouth, eyes, or other openings) + -sis -SIS)) + -idae -ID 2 ]