n a deep prolonged loud noise
n a state of economic prosperity
n a sudden happening that brings good fortune (as a sudden opportunity to make money)
n a pole carrying an overhead microphone projected over a film or tv set
n any of various more-or-less horizontal spars or poles used to extend the foot of a sail or for handling cargo or in mooring
v make a resonant sound, like artillery
v hit hard
v be the case that thunder is being heard
v make a deep hollow sound
v grow vigorously
n. （生意）繁荣( boom的名词复数 ); 深沉的响声; 帆桁
v. 激增( boom的第三人称单数 ); 猛涨; 发出隆隆声; 以低沉有力的声音说话