What do the British call the item of clothing that Americans know as a 'vest'?
Correct answer: Waistcoat

RICK-N-BACHER
it's the third part of a 3 piece suit.

Lionessa
I persuaded my man to buy a tuxedo many years ago when we began dating. It's important to me to have season tickets for the symphony, and a tux is de rigueur. He complained at first, but once he saw his 6'7" self in a tux tailored just for him, he realized he looked great. Now, he's the one who makes sure we have tickets to the symphony each year so he can strut a little.

Byrde Alpha Bitch
CyanJaguar62, Only in certain circles.

ATS
A vest can be thermal, or string, and is classed as underwear. ( Pants are also underwear)

Marcy
wearing long sleeves then the Vest after looks descent to anyone wearing it

Byrde Alpha Bitch
Player #21167188, No, that is an entirely different piece of clothing.