形容詞 epochal:

1. highly significant or important especially bringing about or marking the beginning of a new development or era
   同義詞：epoch-making

1. Epochal decisions made by Roosevelt and Churchill.
   羅斯福和邱吉爾做出的有重大意義的決定

ep.och.al

adj.（形容詞）
Of, relating to, or characteristic of an epoch.
開新紀(jì)元的：與新紀(jì)元或其特征有關(guān)的

Highly significant or important; momentous:
有重大或重要意義的；極其重要的：
例句：
epochal decisions made by Roosevelt and Churchill.
羅斯福和邱吉爾做出的有重大意義的決定

Without parallel:
無與倫比的：
例句：
epochal stupidity.
無與倫比的愚蠢