HSK 5 HSK V5
Correct

一旦

/ yīdàn /
Strokes

Definition

in case (sth happens)/if/once (sth happens, then...)/when/in a short time/in one day

Example

As a Noun

single day; very short time

1
Kuì
dàn
一旦

collapse overnight

2
Huǐdàn
毁于一旦

be destroyed in one day

As a Conjunction

once; in case; now that

3
huì
机会
dàn
一旦
cuòguò
错过
  
,
yǒngyuǎn
永远
huì
不会
zài
lái
  

Once an opportunity slips away, it is gone for good.

4
dàn
一旦
zhìdìng
制订
le
huà
计划
  
,
jiù
yìng
àn
huà
计划
xíngshì
行事
  

Once the plan is all set, you should keep to it.

5
dàn
一旦
shí
时机
chéngshú
成熟

once the time is ripe

Related

毁于一旦