you've got another think coming

you've got another think coming

Your expectations are wrong and unreasonable; you better think again. Almost always preceded by "If you think (something)." The phrase is commonly altered as "you've got another thing coming." If you think you can walk in here and just demand a raise, you've got another think coming. If he thinks he can hit it big without paying his dues, he's got another think coming.
See also: another, coming, think
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

You've got another think coming.

You will have to rethink your position. (The second part of an expression something like, "If you think so-and-so, then you've got another think coming." Also with thing rather than think.) Rachel: If you think I'm going to stand here and listen to your complaining all day, you've got another think coming! Bill: Frankly, I don't care what you do. Andy: If you think you can get away with it, you've got another think coming! Bob: Get away with what? I didn't do anything!
See also: another, coming, think
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

You’ve got another think coming

sent. You have made an error. Think again. (Especially with if. The word think is original, although some speakers change this to thing.) If you think I’m going to let you get away with that, you’ve got another think coming.
See also: another, coming, think
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

you've got another think coming

You’re completely wrong. This phrase from the first half of the twentieth century uses think as a noun meaning “what one thinks about something.” T. Bailey used it in Pink Camellia (1942), “If you think you can get me out of Gaywood, you’ve got another think coming.”
See also: another, coming, think
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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