mantissa 

noun (mantissae)

(obsolete) A minor addition to a text.

(mathematics) The part of a common logarithm after the decimal point.

(mathematics and computing) The significand; that part of a floatingpoint number that contains its significant digits.
 
matrix 

noun (matrices)

(obsolete) The womb. The concept of an enclosure is common to many of the other uses of .

(biology) The material or tissue in which more specialized structures are embedded.

(biology) An extracellular matrix, the material or tissue between the cells of animals or plants.

(biology) Part of the mitochondrion.

(biology) The medium in which bacterium, bacteria are cultured.

(mathematics) A rectangular arrangement of numbers or terms having various uses such as transforming coordinates in geometry, solving system of linear equations, systems of linear equations in linear algebra and representing graphs in graph theory.

(computing) A twodimensional array.
 A table of data.

(geology) A geological matrix, the outer material of a rock consisting of larger grains embedded in a material consisting of smaller ones.

(archaeology) The sediment surrounding and including the artifacts, features, and other materials at a site.

(analytical chemistry) The environment from which a given sample is taken.
 
