determinant

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Determinative.
2. n. An influencing or determining element or factor: "Education is the second most important determinant of recreational participation” ( John P. Robinson).
3. n. Mathematics The value that is computed from a square matrix of numbers by a rule of combining products of the matrix entries and that characterizes the solvablitity of simultaneous linear equations. Its absolute value can be interpreted as an area or volume.
4. n. Immunology An epitope.

Century Dictionary and Cyclopedia

1. Serving to determine; determinative.
2. n. That which determines, fixes, defines, or establishes something.
3. n. In old universities, one who, having taken the lowest degree in arts, had been admitted to act as chief respondent in the Lenten disputations. See determination, 12.
4. n. In mathematics, the sum of all the products which can be formed of a square block of quantities, each product containing as a factor one number from each row and one from each column of the block, and each product being affected by the plus or minus sign according as the arrangement of rows from which its factors are taken (these factors being arranged in the order of the columns from which they are taken) requires an even or an odd number of transpositions to reduce it to the arrangement in the square. A determinant is conventionally denoted by writing the square block of quantities between two vertical lines. For example
5. n. of the r order, a function of r constituents, analogous to an ordinary determinant.
6. n. In biology, in Weismann's doctrine of germ-plasm, the material bearer of all the hereditary qualities of a cell, regarded as composed of as many biophores, or bearers of single hereditary qualities, as are to be possessed by the cell and its descendants.

Wiktionary

1. n. A determining factor; an element that determines the nature of something
2. n. linear algebra The unique scalar function over square matrices which is distributive over matrix multiplication, multilinear in the rows and columns, and takes the value of 1 for the unit matrix. Abbreviation: det
3. n. biology A substance that causes a cell to adopt a particular fate.

GNU Webster's 1913

1. adj. Serving to determine or limit; determinative.
2. n. That which serves to determine; that which causes determination.
3. n. (Math.) The sum of a series of products of several numbers, these products being formed according to certain specified laws.
4. n. (Logic) A mark or attribute, attached to the subject or predicate, narrowing the extent of both, but rendering them more definite and precise.

WordNet 3.0

1. n. the site on the surface of an antigen molecule to which an antibody attaches itself
2. n. a determining or causal element or factor
3. n. a square matrix used to solve simultaneous equations
4. adj. having the power or quality of deciding