1650s, from moment + -ous to carry the sense of "important" while momentary kept the meaning "of an instant of time." Related: Momentously; momentousness.
雙語例句
1. In that year, two momentous discoveries were made.
那一年，有兩個重大發現。
來自柯林斯例句
2. I am deeply honoured to be invited to this momentous occasion.
能應邀出席如此重要的場合,我深感榮幸.
來自《簡明英漢詞典》
3. The momentous news was that war had begun.
重大的新聞是戰爭已經開始.
來自《簡明英漢詞典》
4. Meanwhile, most young people in the West are expected to leave what could be life's most momentous decision—marriage—almost entirely up to luck.
同時，人們認為西方的大多數年輕人把婚姻這一可能是人生最重要的決定幾乎完全交由命運來安排。
來自柯林斯例句
5. The past three years have been among the most momentous in world history.