/'seməfɔ:(r); `sɛmə,fɔr/
n
1 [U] system of sending signals by holding the arms or two flags in certain positions to indicate letters of the alphabet 旗语
*send a message by semaphore 用旗语发送信息.
2 [C] device with red and green lights on mechanically moved arms, used for signalling on railways （铁路的）臂板信号机.

v [I, Tn, Tf, Dpr.f, Dpr.w, Dpr.t nopassive 不用于被动语态] send (messages) by semaphore 用旗语发送（信息）
*semaphore (to sb) that help is needed/to send help （向某人）打旗语求救.

n[U]
[Date: 1800-1900; Language: Greek;Origin: sema 'sign' + -phoros 'carrying']
a system of sending messages using two flags, which you hold in different positions to represent letters and numbers