Running on fumes - To stay awake even when you're exhausted. The student had stayed up for hours studying and felt like he needed to go to sleep soon. He was running on fumes. Run like the wind - To run really quickly. I'm determined to run like the wind during the next track and field meet. Run-of-the-mill - Common and ordinary. I liked the sweater that Amy pointed out, but I honestly felt that it was a bit run-of-the-mill. I could probably find one like it anywhere. Run one's mouth off - To speak too much on something that you shouldn't. I don't want to run my mouth off, but I don't think you should go there tomorrow—and here's why. Run out of steam - To run out of energy. I tried to finish rearranging the furniture yesterday, but I ran out of steam and had to get some sleep. Run the show - To be in charge of something. The manager was determined to run the show in his office.