Quick definitions from WordNet (Guided bomb unit-28)
▸ noun: a 5,000 pound laser-guided bomb that can be programmed to penetrate to a given depth before exploding; used to penetrate hardened underground faccilities
▸ noun: a 5,000 pound laser-guided bomb that can be programmed to penetrate to a given depth before exploding; used to penetrate hardened underground faccilities