(idiomatic) Some period of time, such as a term of employment or a lifetime, is coming to an end.

(quantum mechanics) One of certain integers or half-integers that specify the state of a quantum mechanical system (such as an electron in an atom).

A number written in the form a × bᶜ, e.g. 3.75 × 10³ (a being the mantissa, b, the base and c, the exponent).

A mandatory unique alphanumeric code (usually 17 characters long) assigned to each vehicle produced, stamped into the metal on the dashboard on the left-hand side (viewable through the windshield), and on the engine block and at least one other place somewhere on the body of the vehicle.

(physics, chemistry) The total number of protons and neutrons in an atomic nucleus. Symbol: A

The Book of Numbers, the fourth of the Books of Moses in the Old Testament of the Bible, the fourth book in the Torah.

A telephone number not listed in the directory.

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.