1. To follow along behind someone or something while running. He ran behind the pack for most of the race before surging to the lead just before the finish line. She ran behind the taxi, waving frantically for it to stop.
2. To run to and seek cover behind someone or something. The child ran behind his mother when the police officer came up to say hello. The soldier ran behind the wall to avoid enemy fire.
3. To seek the protection of someone or something, especially in a cowardly or entitled way. She just goes and runs behind his rich daddy whenever she gets into trouble. He always goes and runs behind the First Amendment whenever he gets called out for saying something truly bigoted and evil.
4. To be behind schedule; to be a bit late. Typically used in the continuous tense. Are you ready to leave yet? We're already running behind! Their newest project has apparently started running behind, with the estimated release date moving to Spring of next year.
run behind someone or something
to travel along behind someone or something, running. I will run behind you in the race. Mary ran behind the bicycle until she could not run anymore.
to be late; to run late. We are running behind. You had better hurry. Things are running behind, and we will not finish on time.