acrosome

noun Cell Biology.

1. an organelle covering the head of animal sperm and containing enzymes that digest the egg cell coating, thus permitting the sperm to enter the egg.

noun

1. a cap-like structure on the tip of a spermatozoon that releases enzymes on encountering the ovum allowing fusion with the ovum in the sexual reproductive process; this part of the process is known as the acrosome reaction

n.

1. acrosomal cap