RUN'IN Share definition Flag When a woman spreads her legs and a man runs in. When his wife laid on the bed with her legs spread. The husband came in from the garage and ran in for a glass of water. He had a run'in RUN'IN by Donald K. Butters October 31, 2007 0 0 Get merch Get the RUN'IN mug. Buy Now — $32.95 See more merch