n a process at the anterior end of a sperm cell that produces enzymes to facilitate penetration of the egg
2
a penetration of a barrier such as an enemy's defense
3
affecting one deeply s marked by depth of thinking a having great spatial extension or penetration downward or inward from an outer surface or backward or laterally or outward from a center
4
resistant to penetration by grease or oil or wax
5
Hentai isn't always sexual penetration with a group or pair of people
