cuckolder

A male of certain kinds of fish that interrupts a mating pair to release sperm in an attempt to fertilize the female.

One who commits cuckoldry; one who cuckolds.

The friends of the respective parties, those of the cuckolder on one side, and those of the cuckoldee on the other side; and the public (as far as play-house audiences are the public) have fairly decided in favour of the cuckolder! What an admirable system of “public instruction”!

Gascoigne, Hundreth Sundrie Flowres (1573) 78 has a teasing passage in which cuckold and cuckolder are out hunting.