From Longman Dictionary of Contemporary Englishhunch your shouldershunch your shouldersUPto raise your shoulders into a rounded shape because you are cold, anxious etc → hunch
Examples from the Corpus
hunch your shoulders• Lean away from the flexed knee and keep your guard close to your body, but avoid hunching your shoulders.• Then, hunching his shoulders against the pounding rain, he lurched towards the barn.• Schmidt hunched his shoulders and gobbled like a turkey.• He hunched his shoulders and stamped his way defiantly down the rest of the stairs and out into the cobbled street.• Ballesteros hunched his shoulders, put his palms up in the air, and raised his dark, thick eyebrows.• He put them on, and peered round the room, hunching his shoulders, shamming the old scholar.