talk through your hat
idiomPart ofhat
talk through your hat — idiom
1. to talk confidently about a subject that you know very little about, saying thin
1.idiom
Definition
to talk confidently about a subject that you know very little about, saying things that are not true or sensible.
Example
The reporter was talking through her hat when she claimed the school was closing down.
Don't listen to him about car engines — he's talking through his hat.