Cases of word usage

1) a close-fitting type of underwear shaping the waist and hips (corset)

2) women's underwear (lingerie)

3) underwear (the usual word) (underclothes)

4) male underwear covering the lower part of the body (underpants)

5) women's underwear (undies)

6) (GB) an article of underwear worn on the upper part of the body next to the skin (US = undershirt); (US) a waistcoat; to give (a person) (something) as a fixed right (vest)