Definitions of unforeseen

  1. happening or coming quickly and without warning; "a sudden unexpected development" Scrapingweb Dictionary DB

Usage examples for unforeseen

  1. It had still two weeks to run, unless indeed some unforeseen circumstance interrupted it, some mission which could not be delayed. – The Master of the World by Jules Verne
  2. This is an age when unforeseen attack could come with unprecedented speed. – Complete State of the Union Addresses from 1790 to the Present by Various