Definition
To instruct someone to remain still and not move.
（用以告知某人）不要移动。
You have to hold still so I can take a good picture of you.
你必须保持不动，这样我才能帮你拍张好照片。
Please hold still, the doctor needs to examine your wound.
请保持不动，医生需要检查你的伤口。
Kid, please hold still, I'm measuring your height.
孩子，请保持不动，我在量你的身高。