vb. To shut out; to hinder from entrance or admission; to debar from participation or enjoyment; to deprive of; to except; - the opposite to admit; as, to exclude a crowd from a room or house; to exclude the light; to exclude one nation from the ports of another; to exclude a taxpayer from the privilege of voting. To thrust out or eject; to expel; as, to exclude young animals from the womb or from eggs. Excluded middle. (logic) The name given to the third of the 'three logical axioms,' so-called, namely, to that one which is expressed by the formula: 'Everything is either A or Not-a. ' no third state or condition being involved or allowed. See Principle of contradiction, under Contradiction.