stair

Etymology tree

Proto-Indo-European *steygʰ-

Proto-Indo-European *-eti

Proto-Indo-European *stéygʰeti

Proto-Germanic *stīganą

Proto-Indo-European *-yeti

Proto-Indo-European *-éyeti

Proto-Germanic *-janą

Proto-Germanic *staigijaną

Proto-Indo-European *-rós

Proto-Germanic *-raz

Proto-Germanic *staigraz

Proto-Germanic *staigriz

Proto-West Germanic *staigri

Old English stǣġer

Middle English steire

English stair

From Middle English steire, staire, stayre, stayer, steir, steyre, steyer, from Old English stǣġer (“stair, staircase”), from Proto-West Germanic *staigri, from Proto-Germanic *staigriz (“stairs, scaffolding”), from Proto-Indo-European *steygʰ- (“to walk, proceed, march, climb”).

Cognate with Dutch steiger (“a stair, step, wharf, pier, scaffolding”), Middle Low German steiger, steir (“scaffolding”), German Low German Steiger (“a scaffold; trestle”). Related to Old English āstǣġan (“to ascend, go up, embark”), Old English stīġan (“to go, move, reach; ascend, mount, go up, spring up, rise; scale”), German Stiege (“a flight of stairs”). More at sty.