go back on (something)

go back on (something)

To not do something one said one would do; to renege on something. People are beginning to worry that the president is going to go back on his campaign promises. You made a commitment to support our project, and now you've gone back on your word!
See also: back, go, on
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

go back on

Fail to honor or keep, as in You can't go back on your word, or One should never go back on a promise. [Mid-1800s]
See also: back, go, on
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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