v.tr. Brit. sl.
1. tamper with (a racehorse) to prevent its winning.
2 get hold of (money etc.) dishonestly.
3 catch (a criminal).
4 secure the support of or weaken (a person) esp. by underhand means.
5 seize, grab.
Etymology: prob. dial. knobble, knubble knock, beat, f. KNOB