From Longman Dictionary of Contemporary Englishkeep your head downkeep your head downto try to avoid being noticed or getting involved in something Do what you’re told and keep your head down. → head
Examples from the Corpus
keep your head down• Even his most bitter opponents are keeping their heads down.• Carla kept her head down as she approached the front door, glancing up briefly when the two officers introduced them-selves.• He kept his head down under fire, avoided trouble, trusted in luck to keep him alive.• I have pain in my left shoulder when I keep my head down or in moving my left arm a lot.• I kept my head down and pretended to be consuming the scraps left on my dish.• I kept my head down and the heavy bag well to the fore as a protective shield.• It was good advice to keep my head down in the early months.• But real life, of course, teaches lesser men to keep their heads down and their mouths shut. 