lamprey
n.
c.1300 (c.1200 as a surname?), from Old French lamproie, from Medieval Latin lampreda, from Late Latin lampetra "lamprey," of uncertain origin, usually explained as literally "lick-rock," from Latin lambere "to lick" (see lap, v.1) + petra "rock" (see petrous). The animals attach themselves to things with their sucker-like mouths.