Other forms: shrugged, shrugs, shrugging
To shrug is to lift your shoulders to show that you do not know or do not care. A whole sentence, without a word.
It is one of the most legible gestures there is and it works across most cultures. As a noun a shrug is the gesture itself, and answering with a shrug is a standard piece of description. The phrasal verb shrug something off is the useful one, since it means to dismiss a problem or an injury as unimportant, and a player who shrugs off a knock carries on playing.
A shrug was a crouch. Middle English schruggen is related to Scandinavian words meaning to stoop or to huddle, so raising the shoulders is the body making itself small.
Proto-Germanic
*skrinkwaną
Old Norse
skrykkva
Middle English
schruggen
English, today
shrug
Built from
From Middle English schruggen, shrukken, probably of gmq - origin related to Danish skrugge, skrukke (“to stoop; crouch”), Swedish skruga, skrukka (“to huddle; crouch”), all from or related to Old Norse skrykkva, from Proto-Germanic skrinkwaną. Compare also Old English scrincan (“to shrink”). More at shrink.
Etymology from Wiktionary, CC BY-SA