| 释义 |
null
I. \ˈnəl\ adjective
Etymology: Middle French nul, literally, none, not any, from Latin nullus, from ne- not + ullus any (akin to unus one) — more at no, one
1.
a. : having no legal or binding force or validity : of no efficacy : invalid, void — often used in the phrase null and void
b. : capable of being regarded as void : voidable at the option of an injured party
2. : amounting to nothing : nil, nonexistent
< the null uselessness of the wireless transmitter that lacks a receiving station — Fred Majdalany >
3.
a. : having no value : of no consequence : insignificant
< news as null as nothing — Emily Dickinson >
b. : lacking distinction, character, or personality
< the scene … was pitched in the null, noncommittal surroundings of a rehearsal room — Osbert Sitwell >
4.
a. : having no members : empty
< the null class >
b.
(1) : having the character or value of zero
< the null element >
(2) : having a zero radius
< a null sphere >
5. : indicating usually by a zero reading on a scale when current or voltage is zero — used of an instrument
6. : of, being, or relating to zero
< the photoelectric current through a load resistor produces a voltage drop that is balanced by a potentiometer, thus giving a null reading for each condition of balance — Journal of Research >
7. : relating to the null of a radio receiver
II. noun
(-s)
1.
a. : zero 2a(1)
< a null-reading instrument >
< the various signals can combine so that a substantial null in transmission exists at certain frequencies — B.D.Loughlin >
b. : a condition of a radio receiver existing when minimum or zero signal is received and resulting from adjustment of parts (as rotation of the directional antenna or tuning of the circuit)
2. : a meaningless letter or code group introduced to impede cryptanalysis
III. transitive verb
(-ed/-ing/-s)
Etymology: Medieval Latin nullare, from Latin nullus null, adjective
1. : to reduce to nothing : destroy, expunge, obliterate
2. : to make void : annul, nullify
< the first election he nulled because its irregularity was glaring — Edmund Burke >
< election nulled by the courts >
IV. noun
(-s)
Etymology: by alteration
: knur
V. noun
(-s)
Etymology: by alteration
: knurl 1; especially : a raised convex boss or ornament on a flat surface on a piece of furniture
VI. transitive verb
(-ed/-ing/-s)
Etymology: back-formation from nulling
: knurl
VII. noun
(-s)
Etymology: null (III)
1. : nullo
2. : a game of skat played without a trump suit in which the bidder undertakes to lose every trick
VIII. adjective
1. : having zero as a limit
< null sequence >
2. of a matrix : having all elements equal to zero |