Clasper

noun

1. One that clasps.
2. Any of the appendages of the male of certain insects and crustaceans that are used during copulation to hold the female.
3. A posterior extension on each of the pelvic fins of male cartilaginous fishes that aids in the transmission of sperm during copulation.
4. The operator who makes clasps or attaches them to books or other articles.
5. One who or that which clasps.