once and for all
1. 永远地; 一次了结地
John's back home once and for all.
约翰回到家, 再也不走了。
once in a while
1. 有时
He went to see them once in a while.
他有时去探望他们。
once more/again
1. 再一次
John's back home once more.
约翰又回家了。
once or twice
1. 几次
I've been there once or twice.
我到过那里几次。
once too often
1. 又一次
He exceeded the speed limit once too often.
他又超速行驶了。
all at once
1. 突然
He left all at once.
他突然离开了。
at once
1. 马上; 立刻
Do it at once!
马上就做!
for once
1. 仅此一次
For once he was telling the truth.
他就这一次说了真话。
习惯用语all at once1.突然; 同时at once1.立刻, 马上; 同时every once in a while1.[美]偶而for this once (=for once, just for once)1.就这一次; 破例一回if once (=when once)1.一旦more than once1.不止一次, 多次not once1.一次也不once again1.再一次once and again1.一再, 再三once and away1.一劳永逸; 限此一次; 断然, 爽快once for all1.一劳永逸; 永久地; 彻底地once in a while1.有时, 间或, 偶而once more1.再一次once again1.再一次once or twice1.一两次; 有时, 偶尔once over lightly1.从头到尾马马虎虎地once too often1.又(多了)一次