1. knocking
2. sound, roast
3. criticism, critique, bash
4. bang, smash, belt, bump, blow, misfortune
5. bad luck, belt

1. rap, whack, whang, blow, strike hard
2. strike, knock over, knock down, knock out, knock cold, rap
3. knap, bump
4. hit, strike, impinge on, run into, collide with, knock against, knock about, tap
5. rap, pink, sound, go, pink
6. ping, sound, go, criticize
6. criticise, pick apart, comment, notice, remark, point out