Green’s Dictionary of Slang

cheaters n.2

[they help the male genitals, eyes, teeth or female breasts cheat their own inadequacies]

1. [20C+] (orig. US, also cheaters eyes, cheeters, eye cheaters) glasses, spectacles, esp. dark glasses; thus smoke cheaters, dark glasses.

2. [1910s–70s] close-fitting men’s underpants, usu. with elastic legbands.

3. [1940s+] pads which are placed in a brassiere to suggest a fuller breast.

4. [1950s+] (orig. US) false teeth.