What is a Freudian slip?

A Freudian slip is when someone says one thing when thinking of amother. 

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Ang2dogs wrote:When I was working ina deli, a nice looking woman came in and asked for about 2lbs of lean beef,
well my mouth decided to overide my brain, and I said, "well I get off work at 4 o'clock".
Talk about that moment of dead silence, I joined the military that week,
her husband wanted to shoot me!