Answer: flails

AnswerCrossword Clue
FLAILS

Grain threshers

FLAILS

Swings wildly

FLAILS

Waves one's arms wildly

FLAILS
Resists being handcuffed, maybe
FLAILS
Threshes.
FLAILSThreshing instruments.
FLAILSThreshers
FLAILSHand threshers
FLAILSBeats
FLAILSWaves wildly
FLAILSGives a thrashing
FLAILSThrashes about