1.Definition: departing from the normal in e.g. intelligence and development
"They were heartbroken when they learned their child was abnormal", "An abnormal personality"
2.Definition: much greater than the normal
"Abnormal profits", "Abnormal ambition"
3.Definition: not normal; not typical or usual or regular or conforming to a norm
"Abnormal powers of concentration", "Abnormal amounts of rain", "Abnormal circumstances", "An abnormal interest in food"