1. with repeated sharp blows; whack after whack; with crack after crack (of a whip); hard and repeatedly (striking) (Onomatopoeia, Colloquial)

2. strictly; harshly; without holding back; relentlessly (Onomatopoeia, Colloquial)

3. vigorously; singlemindedly; wholeheartedly; energetically (Onomatopoeia, Colloquial)