/wah"wah'/ , adj.
1. producing a muted, bawling sound like that of a trumpet with the hand moved momentarily over the bell: a wah-wah effect on a synthesizer; a guitar with a wah-wah pedal.
n.
2. a sound or effect like the muted sound of a trumpet, esp. in music.
3. an electronic device or attachment to produce such a sound, often used with an electric guitar.
Also, wa-wa .
[ 1925-30; imit. ]