ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: Middle English nightgoun, from night (I) + goun gown
1. archaic : a loose gown suitable for wear on evenings at home : dressing gown
found him … wrapped in a tartan nightgown — Sir Walter Scott
2. : a garment resembling a dress or shirt designed for wear in bed
she rose in her pale nightgown — W.B.Yeats
stockinet nightgowns are comfortable … for the baby — Benjamin Spock