形容詞 irrevocable:

1. incapable of being retracted or revoked- Shakespeare
   同義詞：irrevokable

1. In irrevocable letter of credit in your favour, payable in ... against shipping documents.
   如果我方接受你方發(fā)盤，將開立以你方為受益人的不可賒銷信用證在。。。付款交單。
2. The decision has been made and is irrevocable.
   木已成舟已作出決定，無法反悔
3. Jove gives his promise, and confirms it with the irrevocable oath, attesting the river Styx, terrible to the gods themselves.
   朱庇特應允了，還發(fā)誓絕不食言，且指定冥河斯提克斯——眾神聽了都要發(fā)抖的名字——做他的監(jiān)誓人。
4. I am sorry to say the only term of payment we can accept is100% irrevocable documentary letter of credit.
   抱歉地說，我們能接受的付款條件只有100％不可撤銷跟單信用證。

ir.rev.o.ca.ble

adj.（形容詞）
Impossible to retract or revoke:
不能撤回的或不可廢止的：
例句：
an irrevocable decision.
不能撤回的決定

【引伸】
irrev.ocabil.ity 或
irrev.ocableness
n.（名詞）
irrev.ocably
adv.（副詞）