Word used largely in Eastern Tennessee to describe a man's large penis. Also can be used in the shorter form diesel, to describe a really outstanding or "cool" individual. However word is not interchangable with cool/nice etc. It is specifically used for a certain way of acting.
Individuals referred to as Diesel usually have the following traits:
1. crudely humored.
2. Usually Pyschically Large (and in charge)
3. Open mind to their own ideas.
4. When ever possible will express dominance on weaker people.
5. May drive a cadillac, BMW, Chrysler, Landrover, or Peugot (in europe only)
6. Often will enjoy fanship of contact sports
7. When asked his interest will repond as follows: A good meal and a hot woman.
"Hey Diesel Whats up?"
"Thats Big diesel over there"
"Oh Diesel do it harder"
"Yes my name is Diesel, but you can call me Daniel or what ever"