He was guilty of a blunder.

He made ten blunders in as many lines.

A-ha-ha-ha! What a blunder!

Tom seems to have blundered again.

What a blunder!

He pleaded for me when I made a blunder.

You should leave me cool; otherwise, I will say a possible blunder!

The boss called him out for his blunders.

You should leave me cool; otherwise, I will say a possible blunder.

The leader of the separatists will never be able to rectify his political blunders.