boom
/bu:m; bum/ v
1 [I, Ip] make a deep hollow resonant sound 发出深沉、有回响的声音
waves booming on the seashore 撞击海岸发出隆隆声的海浪
We could hear the enemy guns booming (away) in the distance. 我们能听到远处敌人的大炮轰隆声.
The headmaster's voice boomed (out) across the playground. 校长瓮声瓮气的声音传遍操场.
2 [I, Ip, Tn, Tn.p]
~ (sth) (out) utter (sth) in a booming voice 用深沉的嗓音讲（话）
`Get out of my sight!' he boomed. ｀走开!＇他用低沉的声音说. boom, n (usu sing 通常作单数) deep hollow sound 深沉的声音
the boom of the guns, the surf 大炮、波涛拍岸的隆隆声.
boom / bu:m; bum/ n sudden increase (in population, trade, etc); period of prosperity （人口、贸易等的）突然增加; 繁荣昌盛时期
The oil market is enjoying a boom. 石油市场欣欣向荣.
[attrib 作定语]
a boom year (for trade, exports, etc) （贸易、出口等）繁荣昌盛的一年. boom, v [I] have a period of rapid economic growth 处於经济迅速发展时期
Business is booming. 商业正在迅速发展.
boom / bu:m; bum/ n
1 (on a sailing-boat) long pole used to keep the bottom of a sail stretched 帆的下桁; 帆杠. =>illus at yacht 见yacht之插图.
2 (also derrick boom) pole attached to a derrick crane, used for loading and unloading a cargo 吊杆.
3
(a) barrier (usu of heavy chains) placed across a river or harbour entrance as a defence against enemy ships 横江铁索（用以防御敌舰）.
(b) barrier (usu a mass of logs) placed across a river to prevent logs from floating away 水栅（通常为圆木, 用以防止木材漂走）.
4 long movable arm for a microphone 话筒的可移动长臂
[attrib 作定语]
a boom microphone 有可移动长臂的话筒.