noun, noun or participle which takes 'suru', intransitive verb
Refers to a small, often involuntary or restrained movement of the body; frequently used in negative expressions like 身じろぎもしない (not moving a muscle).
彼は身じろぎもせずに立っていた。
He stood without stirring.
赤ちゃんが寝ている
The baby didn't make a single movement while sleeping.