1) Bringing ruin 2) Controlled or decreed by fate 3) Decisive 4) Fatal 5) Foreboding 6) Having momentous consequences 7) Momentous 8) Ominous 9) Ominously prophetic 10) Predetermined 11) Prophetic 12) Significant 1) Calamitous 2) Decisive 3) Disastrous 4) Fatal 5) Foreboding 6) Inevitable 7) Prophetic 8) Prophetical 9) Unfortunate 10) Unlucky 
• (a. .) Having the power of serving or accomplishing fate. • (a. .) Significant of fate; ominous.
Fate'ful adjective . Having the power of serving or accomplishing fate. 'The fateful steel.' J. Barlow. 2. Significant of fate; ominous. « The fateful cawings of the crow.» Longfellow. -- 
[adj] - of ominous significance 2. [adj] - having momentous consequences
fateful 1. After which an important, often dire consequence, seems to have been made inevitable. 2. Predetermined or controlled by fate. 3. Foretelling what is to come; especially, when it is something disastrous. Cross references of word families related directly, or indirectly, to: 'talk,...
fatal adjective 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`