Any program or trick to find the definition of a variable?

Question

Many times when I am watching others code I just want to find where and how a variable is defined. Normally what I do now is look for the type of the variable until I find t

Answer 1

You've already given the most appropriate tool: an IDE. This is exactly the kind of thing which an IDE excels at. Why would you not want to use an IDE if you're finding development painful without one?

Note that Emacs, Vim etc can work as IDEs - I'm not talking about forcing you the world of GUIs if you want to stay in a text-only situation, e.g. because you're SSHing in.

(I'm really not trying to be rude here. I just think you've discounted the obvious solution without explaining why.)