(Verb.) To workout in an extreme fashion (usually having to do with MMA) or to overcome an opponent while using skill and technique as opposed to brute force.
Diesel is a code word used in front of children, grandmother's, and the sensitive individuals to communicate with your partner that you want the sex and you want it right now.
"There's been a diesel running up and down this train, causing all sorts of fucking havoc."
"Yeah, I still feel like there's a diesel lurking about."
"Man, I'm trying to get diesels out of my life, you know?'
"'Cause diesels bluff, they go too far."