Other forms: slouching, slouched
To slouch is to sit or stand with a drooping back. Shoulders forward, spine curved, all the air gone out of you.
It is the posture of boredom and teenage indifference, which is why it attracts so much telling off — sit up, don't slouch. As a noun it means the posture itself, and a slouch hat is one with a soft drooping brim. There is one idiom that runs the other way, since saying somebody is no slouch means they are very good indeed at the thing in question.
1verbslouchTo sit, stand or move with a drooping posture.
“He slouched in the doorway with his hands in his pockets.”
Latin
laxus — loose, slack
Swedish
slak — slack, soft and flexible
Old Norse
slókr — lazy fellow
Middle English
slugge
English, today
slouch
Unclear. Perhaps from Middle English slugge, from Old Norse slókr (“lazy fellow”). See also Swedish sloka (“to slouch, wilt”), related to Swedish slak (“slack, soft and flexible”) and Latin laxus (“loose, slack”).
Etymology from Wiktionary, CC BY-SA