I have a Fender Blues Jr. that is a hot rod. Love the sounds that thing makes. I also played a Telecaster the other that has been hot rodded and loved the sound. What does this mean, though? It seems that I like it, but what is different than normal? I've always just gone with the mantra of playing what I like, but I want to start learning the details.

And while we're at it, what would be a good definition of NOS?

Don't Quote me on any of this... I'm just taking educated Guesses ;)

I believe Hot Rodded to mean that someone has changed alot of components on the guitar (Like the neck)

NOS means New Old Stock, and is when they recreate old specs of a guitar but new.

Again, Not sure on this but it might help you in some way :p

And while we're at it, what would be a good definition of NOS?

NOS means only one thing period.

NOS New Old Stock
It is NOT A REPOP.
It is brand new, unused, original stock that was never sold.
Usually still in the original package. Car parts specifically are like this.

Factories rarely have the original dye equipment to reproduce parts, so repops are generally made by copying another part. Then it is never exactly what the original was.

A guitar could have hung in a music store for 20 years and still be NOS.
The store should still have the invoice from the factory showing that it came to them directly if it is truly NOS.
If it was sold and returned, it is now a used guitar, period.

There is a lot of mis-information out there about NOS.

The term "hot rod" originated in the '20s to mean old cars (Ford Model Ts at the time) stripped down and modified to run fast- the word "chopper" describes similar treatment to a motorcycle. In guitar speak, anything with aftermarket modifications can be said to be "hot rodded", although the more radical the modification is, the more appropriate the term is. However, Fender has a "hot rod" line of guitars and amps which are by definition not actually hot rods, since they're regular production pieces that come that way from the factory. Really, it can mean anything you want. "Hot Rodding" is in the eye of the beholder, too- one man's "hot rod" is another man's hatchet job.

GVDobler pretty much nailed what NOS means.

When I hot-rod a guitar... I usually consider that to be ONLY a volume knob with some kind of filter cap going on. If you have 2 pickups you could have a Volume and a 3-way and it would still be a hot-rod.

EVH hot-rodded his strats cause of the simple circuit. The Setzer Hot-Rod is one vol and a 3-way also. I've hot-rodded some guitars.