Definitions for jockstrapˈdʒɒkˌstræp
Random House Webster's College Dictionary
an elasticized belt with a pouch for supporting the genitals, worn as an undergarment by men esp. while participating in athletics.
Ref: Also called athletic supporter.
Origin of jockstrap:
1895–1900; jock male organ (cf. jack in sense “male” and jockey ) +strap
athletic supporter, supporter, suspensor, jockstrap, jock(noun)
a support for the genitals worn by men engaging in strenuous exercise
An athletic supporter worn by men to support the genitals during strenuous exercise.
Origin: from the earlier forms bike jockey strap and jockey strap.