(chemistry, physics) The number of atoms present in 12 grams of isotopically pure carbon-12, being 6.02214076 × 10²³. By definition, the number of elementary entities (atoms or molecules) comprising one mole of a given substance.

(informal) To damage; to treat harshly; to produce ill effects in.

(physics) A dimensionless parameter that determines the behavior of viscous flow patterns. In pipe flow a value less than about 2,000 (known as the critical Reynolds number) produces laminar flow, one above about 3,000 produces turbulent flow (intermediate values produce unpredictable behavior).

The number (street address) assigned to a particular house to distinguish it from other buildings on the same street.

(Canada, US) A toll-free telephone number.

A sequence of numbers indicating order or otherwise used for identification. / The action of creating or assigning such a sequence for identification. / The action of counting or ordering with numbers.

present participle of number

A unique number assigned by IANA to identify objects that are defined by an enterprise.

plural of Arabic numeral

Without number; having too many to count.