If you refer to a decision, event, or change as ~, you mean that it is very important, often because of the effects that it will have in the future.
...the ~ decision to send in the troops...
ADJ
If you refer to a decision, event, or change as ~, you mean that it is very important, often because of the effects that it will have in the future.
...the ~ decision to send in the troops...
ADJ
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012