protective cup; groin guard
Specifically refers to padding or armor covering the testicles, used in sports or historical armor.
In kendo matches, a groin guard is worn.
urinal shield; splash guard
Refers to the hood or mantle on a urinal or squat toilet that prevents splashing.
The urinals in public restrooms have splash guards.
Formed from 金, referring euphemistically to the male genitals, and 隠し, “concealing.” It was applied both to a protective groin cup and to the shield on a traditional urinal.