<p><strong>Noun</strong></p><ul><li>a determining agent or factor</li><li>Mathematics: an algebraic expression of the sum of products of elements, each with an appropriate algebraic sign, usually written in a square array and used in the solution of systems of linear equations</li><li>Also called antigenic determinant</li><li>Immunology: any site on an antigen molecule at which an antibody can bind, the chemical structure of the site determining the specific combining antibody</li><li>Genetics Archaic: a gene</li></ul>