yī​dàn HSK5

once

Senses

一旦 yī​dàn (also yí​dàn) once

in case something happens; if one day; whenever; used to introduce a hypothetical situation or a condition that leads to a specific result

一旦 yī​dàn (also yí​dàn) in a single day

in a very short time; within a single day

References

same_as 一朝/一朝 一旦/一旦