Meaning of NULL in English

NULL

[null] adj [MF nul, lit., not any, fr. L nullus, fr. ne- not + ullus any; akin to L unus one--more at no, one] (ca. 1567) 1: having no legal or binding force: invalid

2: amounting to nothing: nil

3: having no value: insignificant

4. a: having no elements "~ set" b: having zero as a limit "~ sequence" c of a matrix: having all elements equal to zero

5. a: indicating usu. by a zero reading on a scale when a given quantity (as current or voltage) is zero or when two quantities are equal--used of an instrument b: being or relating to a method of measurement in which an unknown quantity (as of electric current) is compared with a known quantity of the same kind and found equal by a null detector

6: of, being, or relating to zero 7: zero 1c

[2]null n (1605) 1: zero 3a(1)

2. a: a condition of a radio receiver when minimum or zero signal is received b: a minimum or zero value of an electric current or of a radio signal [3]null vt (1643): to make null

Merriam-Webster English vocab.      Английский словарь Merriam Webster.