v. & n.
v.intr. 1 shiver esp. convulsively from fear, cold, repugnance, etc. 2 feel strong repugnance etc. (shudder to think what might happen). 3 (of a machine etc.) vibrate or quiver.
n. 1 the act or an instance of shuddering. 2 (in pl.; prec. by the) colloq. a state of shuddering. shudderingly adv. shuddery adj.
[ ME shod(d)er f. MDu. schuderen, MLG schoderen f. Gmc ]