Normal; number; negative.
[The initial letter of these words.]
In chemical formulae, often with a capital letter, this prefix indicates an unbranched chain of carbon atoms: n-hexane, N-acetylcysteine. In mathematics, it is a symbol for an unspecified or variable number; n-gon, a polygon with an unspecified number of sides; n-tuple, an entity or set consisting of an unspecified number of parts or elements. It can also be an abbreviation of negative: n-type, denoting a region in a semiconductor in which electrical conduction is due chiefly to the movement of electrons, as opposed to p-type.