内衣和睡衣的英文单词是一样的吗?

不一样,都各有好多种说法,内衣我喜欢用"underwear",睡衣则用"nighty",好记.
附词霸解释:
内衣
underwear
underclothes
shirt
underdress
undergarment
睡衣
bedgown
gown
night-suit
nighty
pajamas
pyjamas