hold still

hold still

1. To remain motionless or stop moving. Often said as an imperative. Please, hold still! The longer you keep fidgeting, the longer it'll take to put on this sunblock! You'll need to hold still while the MRI machine is running.
2. To cause, direct, or force someone or something not to move very much or at all. In this usage, a noun or pronoun is used between "hold" and "still." The muscle spasms make it impossible to hold my leg still at night. She tried to hold the child still while the doctor examined him.
See also: hold, still
Farlex Dictionary of Idioms.

hold still

(for someone or something) and keep still (for someone or something); stand still (for someone or something) to remain motionless for someone or something. Hold still for the doctor and the shot won't hurt. Please keep still for the doctor.
See also: hold, still
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • stay still
  • keep still
  • keep still (about something)
  • the bloom is off the peach
  • the blush is off the peach
  • be out of (one's) hair
  • get out of (one's) hair
  • get out of hair
  • moot point
  • moot question