A telephone number not listed in the directory.

of or pertaining to numbers / (obsolete) The same in number; hence, identically the same; identical.

(arithmetic) The number or expression written above the line in a fraction (such as 1 in ½). / An enumerator; someone who counts.

(computing) A system for representing numbers in which a radix of two is used; that is, each digit in a binary numeral may have either of two different values.

A number whose decimal representation ends in one or more zeroes. / A rough approximation, especially one whose decimal representation ends in one or more zeroes.

(computing) A number represented by the binary digits 0 and 1.

(set theory) Any cardinal or ordinal number which is larger than any finite, i.e. natural number; often represented by the Hebrew letter aleph (ℵ) with a subscript 0, 1, etc.

(mathematics) any irrational number that is not an algebraic number

A unique number, assigned to a particular unit of some product, to identify it.

(mathematics) A number expressed in the decimal system (base ten), (particularly) fractional numbers so represented.