a person who gives a speech at a public event

a good public speaker 擅长公开演讲的人

Please join with me in thanking our guest speaker tonight. 请大家和我一起向今晚的特邀演讲人表示感谢。

The Democrats have chosen the Texas state treasurer as the keynote (= most important) speaker at their convention. 民主党人选择了得克萨斯州财政部长作为他们大会上的主要发言人。

someone who speaks a particular language

a French speaker 说法语的人

a fluent Russian speaker 说一口流利的俄语的人

non-English speakers 不是说英语的人

the part of a radio, television, or computer, or of a piece of electrical equipment for playing recorded sound, through which the sound is played. A speaker can be part of the radio, etc. or be separate from it

There's no sound coming out of the right-hand speaker. 右边的喇叭不出声了。

the person who controls the way in which business is done in an organization which makes laws

He served for eight years as Speaker of the House of Representatives. 他做了8年的众议院议长。

[ as form of address ] Mr Speaker, my honourable friend has failed to consider the consequences of his proposal. 议长阁下，我尊敬的朋友没有考虑到他的提案的后果。