at worst

[at worst] or [at the worst] {adv. phr.} 1. Under the worst conditions; as the worst possibility.

When Don was caught cheating in the examination he thought that at worst he would get a scolding.

Compare: AT MOST. Contrast AT BEST.

2. In the least favorable view, to say the worst about a thing.

The treasurer had certainly not stolen any of the club's money; at worst, he had forgotten to write down some of the things he had spent money for.