n (chemistry) The combining capacity of an atom, radical or functional group determined by the number of electrons that it will lose, gain, or share when it combines with other atoms etc
n (linguistics) The number of arguments that a verb can have, including the subject of the verb in the counting, ranging from zero (for the likes of "It rains") to three (for the likes of "He gives her a flower").
n (psychology) A one-dimensional value assigned to an object, situation, or state, that can usually be positive or negative