(v.) To use a new example of machinery at a low pace to allow the parts to wear into each other.
Run this car in by keeping it under 6,000 rpm for 1,000 miles.
by Kung-Fu Jesus May 05, 2004
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
by Donald K. Butters October 16, 2007
Occurs when one or more individuals who are not actively participating in a match run into the ring.
Oh, shit! There happened a run-in!
by Lock_Out August 01, 2008