up to no good

idiomPart ofgood

up to no good — idiom

1. Doing something bad, dishonest, or that someone else would disapprove of.

1.idiom
Definition

Doing something bad, dishonest, or that someone else would disapprove of.

Example

The security guard noticed two men acting suspiciously and guessed they were up to no good.

Whenever the children are quiet for too long, Quinn knows they are up to no good.

2. doing something bad or dishonest.

2.idiom
Definition

doing something bad or dishonest.

Example

The children were quiet for too long, so their mother knew they were up to no good.

I saw a stranger near the cars — I think he was up to no good.