a foregone conclusion
1. An inevitable result. After how poorly the team has played so far this season, it's a foregone conclusion that they won't make it to the championship.
2. A view or belief that one has before receiving all pertinent information. Don't come to any foregone conclusions about the accident, all right? Let me tell you the whole story first.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
a ˌforegone conˈclusiona result that is certain to happen: It’s a foregone conclusion that Spain will win tonight’s match.
Farlex Partner Idioms Dictionary © Farlex 2017
foregone conclusion, a
A result that is already known and therefore is taken for granted. The term comes from Shakespeare’s Othello (3.3), in which, after hearing Iago’s lie about Cassio talking in his sleep of his love affair with Desdemona, Othello says this “dream” is a “foregone conclusion”—that is, it clearly denotes that his wife has been unfaithful to him with Cassio (as Iago intended him to believe all along). Some four centuries later the term is still around: “But it could be argued that it was a surprise so many Spaniards were prepared to take part in a vote which was a foregone conclusion” (Economist, Feb. 26, 2005).
See also: foregone
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer