whip - an instrument with a handle and a flexible lash that is used for whipping

eubacteria, eubacterium, true bacteria - a large group of bacteria having rigid cell walls; motile types have flagella

sperm, sperm cell, spermatozoan, spermatozoon - the male reproductive cell; the male gamete; "a sperm is mostly a nucleus surrounded by little other cellular material"

appendage, outgrowth, process - a natural prolongation or projection from a part of an organism either animal or plant; "a bony process"