/si lay"kee euhn/ , adj.
1. belonging to the Selachii, a group of fishes comprising the sharks, skates, and rays.
n.
2. a selachian fish.
[ 1825-35; Selachi ( i ) (pl.) name of the order ( seláchios (sing.) resembling a shark, cartilaginous, adj. deriv. of seláchos shark, ray) + -AN ]