boom
noun uk/buːm/ us/buːm/
(SOUND)
[ C ]低沉有回响的声音;隆隆声
a deep and loud hollow sound
(PERIOD OF GROWTH)
[ C or U ]（经济上的）繁荣;迅速发展
a period of sudden economic growth, especially one that results in a lot of money being made
The insurance business suffered from a vicious cycle of boom and bust. 保险业经历了繁荣和萧条的恶性循环。
the property boom 房地产业的繁荣
[ C usually singular ]增长，繁荣；增长期，繁荣期
an increase in something , or a time when something becomes more popular
This year has seen a boom in book sales. 今年图书销售激增。
See also: baby boom
(BOAT)
[ C ] sailing specialized帆桁;张帆杆
(on a boat) a long pole that moves and that has a sail fastened to it
(FILMING)
[ C ]（电视或电影制作中的）话筒吊杆
a long pole with a microphone on one end that is held above the actors so that it records their voices but cannot be seen by the people watching, used in television and film-making
boom
verb uk/buːm/ us/buːm/
(MAKE A SOUND)
[ I or T ]发出低沉有力的声音;发出隆隆声，轰鸣
to make a very deep and loud hollow sound
The cannons boomed (out) in the night. 晚上传来隆隆炮声。
He boomed (out) an order to the soldiers. 他低沉有力地向士兵们发出命令。
(GROW)
[ I ]增长；迅速发展
to increase or become successful and produce a lot of money very quickly
often in continuous tenses The leisure industry is booming. 休闲产业正在蓬勃发展。