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.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
(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.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.