Intimate apparel and Underclothing

Intimate apparel noun - Women's underwear and nightclothes.

Underclothing and intimate apparel are semantically related. In some cases you can use "Underclothing" instead a noun phrase "Intimate apparel".

Underclothing noun - Clothing intended to be worn underneath other clothing.

Intimate apparel and underclothing are semantically related. Sometimes you can replace phrase "Intimate apparel" with "Underclothing", this terms are similar.