Entry 2 senses · 2 variants Webster, 1913 Upstairs /əp-stĕrz'/ · Up·stairs · IPA /ˌʌpˈstɛɹz/ adv. a. 01 adv. Up the stairs; in or toward an upper story. 1. Up the stairs; in or toward an upper story. 02 a. Being above stairs; as, an upstairs room. 1. Being above stairs; as, an upstairs room.