Ah, wah wah...sounds like I'm talking gibberish (or more than normal!)

A wah pedal makes the guitar produce a...you guessed it, a "wah wah" sound as you move it forward and backwards. Jimi Hendrix and Eric Clapton are two main players that I can think of immediately that use a wah pedal extensively.

You know the sound of a wah pedal...you're just ashamed to admit it. You LOVE the wah! (OK, I'm done now...)