dressing gown
noun [ C ] uk/ˈdres.ɪŋ ˌɡaʊn/ us/ˈdres.ɪŋ ˌɡaʊn/
（室内穿的长而宽松的）晨衣，浴袍
a loose piece of clothing like a coat, worn informally inside the house, especially before getting dressed in the morning or after getting undressed in the evening
Compare: bathrobe