it declared war on North Korea"- Saturday Rev; "the fatal day of the election finally arrived" of ominous significance
having momentous consequences; of decisive importance; "that fateful meeting of the U N when it declared war on North Korea"- Saturday Rev; "the fatal day of the election finally arrived"
(of events) having extremely unfortunate or dire consequences; bringing ruin; "the stock market crashed on Black Friday"; "a calamitous defeat"; "the battle was a disastrous end to a disastrous campaign"; "such doctrines, if true, would be absolutely fatal to my theory"- Charles Darwin; "it is fatal to enter any war without the will to win it"- Douglas MacArthur; "a fateful error"
If an action or a time when something happened is described as fateful, it is considered to have an important, and often very bad, effect on future events. It was a fateful decision, one which was to break the Government. = momentous. having an important, especially bad, effect on future events fateful day/night/year etc