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1.
A person who changes moods suddenly and unpredictably. You never know what they are thinking or how they will react. Smiling one moment, frowning the next, then scowling, and its all going on inside, because the person is not responding to any, apparent external event.
She was smiling, then she snapped at me for no apparent reason--what a mood pot.
by Dr. Foo August 10, 2009