Shake  —v. (-king; past shook; past part. Shaken) 1 move forcefully or quickly up and down or to and fro. 2 (cause to) tremble or vibrate. 3 agitate, shock, or upset the composure of. 4 weaken or impair in courage, effectiveness, etc. 5 (of a voice, note, etc.) Tremble; trill. 6 gesture with (one's fist, a stick, etc.). 7 colloq. Shake hands (they shook on the deal). —n. 1 shaking or being shaken. 2 jerk or shock. 3 (in pl.; prec. By the) colloq. Fit of trembling. 4 mus. Trill. 5 = *milk shake.  no great shakes colloq. Mediocre, poor. Shake down 1 settle or cause to fall by shaking. 2 settle down; become established. Shake hands (often foll. By with) clasp hands as a greeting, farewell, in congratulation, as confirmation of a deal, etc. Shake one's head turn one's head from side to side in refusal, denial, disapproval, or concern. Shake off get rid of or evade (a person or thing). Shake out 1 empty by shaking. 2 open (a sail, flag, etc.) By shaking. Shake up 1 mix by shaking. 2 restore to shape by shaking.