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general::
Phrase(s): go off half-cocked
Fig. to go into action too early or without thinking. (Originally refers to a flintlock or matchlock gun firing prematurely, before the trigger was pulled.) • Don’t go off half-cocked. Plan out what you’re going to do. • Bill went off half-cocked and told everybody he was running for the state legislature.
McGrawhill's American Idioms And Phrasal Verbs