Uncertain; possibly from go-between. It is sometimes considered an acronym and spelled GOBO, but this may in fact be a folk etymology.
gobo (plural gobos)
- (film, television) A disc placed between a light and the illuminated object or actor in order to diffuse the glare.
- (theater) A template inserted over a light source in order to control the shape of the thrown light.
- A device used to shield a microphone from extraneous sounds.