One that changes something: an inveterate changer of decor. (noun)
A device that causes each of a series of audio or audiovisual recordings to be played automatically: a record changer; a compact disk changer. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "changer" in a sentence
"I'm not sure why this thing not being a game changer is important: with the remaining number of primaries a big-margin victory in each of those primaries is of an extreme importance to Hillary, so it was the game changer in a way that it says loud and clear "Hillary, stop pretending that you can win.""
"Either way, we have to remember that, judging from what we have been told by the producers, the game-changer is going to represent a change to the KIND of story that is being told, and not merely the introduction of a new layer of conspiracy or whatever."
"One can almost envision the coin changer on his belt."