no obj.
1- make continual twisting, squirming movements or contortions of the body（不断）扭动, 蠕动（身体）：
he writhed in agony on the ground.
他痛苦地在地上打滚。
1.1
- with obj. cause to move in such a way使扭动, 使蠕动：
a snake writhing its body in a sinuous movement.
一条扭动身体蜿蜒而行的蛇。
1.2
writhe in/with/at
respond with great emotional or physical discomfort to (a violent or unpleasant feeling or thought)遭受苦难; （对…）感到极度痛苦：she bit her lip, writhing in suppressed fury.
她咬着唇, 痛苦地极力压抑住狂怒。
- rare a twisting, squirming movement〈罕〉扭动, 蠕动。
词源
Old English wrīthan 'make into coils， plait， fasten with a cord'， of Germanic origin; related to WREATHE.