shrug (n.)

a shoulder motion meant to express indifference, want of an answer, etc., 1590s, from shrug (v.).

shrug (v.)

c. 1400, schurgyng, of uncertain origin. Perhaps connected to Danish skrugge "to stoop, crouch." Related: Shrugged; shrugging. To shrug (something) off "dismiss" is recorded from 1909.