don't worry; nothing to fear; everything is under control
A reassuring set phrase used to tell someone there is no cause for concern. Often used in spoken or written reassurances.
Don't worry, it'll definitely go well.
There's no need to worry. Everything is ready.
Compound of 心配 (worry) and 無用 (useless, unnecessary). The exact historical derivation is uncertain, but the phrase is conventionally understood as 'worry is unnecessary'.