Allegro was a ground-based, cryogenic resonant Weber bar, gravitational-wave detector run by Warren Johnson, et al. at Louisiana State University in Baton Rouge, Louisiana. The detector was commissioned in the early 90's, and was decommissioned in 2008.
Noun 1. a brisk and lively tempo (hypernym) tempo, pacing (hyponym) allegro con spirito 2. a musical composition or passage performed quickly in a brisk lively manner (hypernym) musical composition, opus, composition, piece, piece of music Adjective 1. (of tempo) fast (similar) fast Adverb 1. in a quick and lively tempo; "play this section allegro" (classification) music