WordNet (r) 3.0 (2006):
let loose v 1: express audibly; utter sounds (not necessarily words); "She let out a big heavy sigh"; "He uttered strange sounds that nobody could understand" [syn: utter, emit, let out, let loose] 2: turn loose or free from restraint; "let loose mines"; "Loose terrible plagues upon humanity" [syn: unleash, let loose, loose]