Acrosome

noun

1. A caplike structure at the anterior end of a spermatozoon that produces enzymes aiding in egg penetration.
2. In cytology, the body which forms the extreme anterior portion of the spermatozoön. Von Lenhossek, 1897.
3. A structure forming the end of the head of a spermatozoon.
4. a process at the anterior end of a sperm cell that produces enzymes to facilitate penetration of the egg