null

Etymology

Borrowed from Middle French nul, from Latin nūllus.

noun

1. A non-existent or empty value or set of values.
2. Zero quantity of expressions; nothing.
3. Something that has no force or meaning.
4. (computing) The null character; the ASCII or Unicode character (␀), represented by a zero value, which indicates no character and is sometimes used as a string terminator.
5. (computing) The attribute of an entity that has no valid value.
   Since no date of birth was entered for the patient, his age is null.
6. One of the beads in nulled work.
7. (statistics) The null hypothesis.

adj

1. Having no validity; "null and void".
   And however Firmilian and S. Cyprian might be deceived in the thinking hereticks quite loſt their orders ; yet in this they were untouched, that although their ſuppoſition was queſtionable, yet their ſuperſtructure was not meddled with, viz. That if they had been Lay-perſons, their Baptizations were null and invalid. a. 1667, Rev. Jeremy Taylor, “Clerus Domini: or, A Discourse of the Divine Institution, Necessity, Sacredness, and Separation of the Office Ministerial”, in Ενιαυτος: A Course of Sermons for All the Sundays Of the year, 3rd edition, London: E. Tyler, page 19
2. Insignificant.
   In proportion as we descend the social scale our snobbishness fastens on to mere nothings which are perhaps no more null than the distinctions observed by the aristocracy, but, being more obscure, more peculiar to the individual, take us more by surprise. 1924, Marcel Proust, Within a Budding Grove
3. Absent or non-existent.
4. (mathematics) Of the null set.
5. (mathematics) Of or comprising a value of precisely zero.
6. (genetics, of a mutation) Causing a complete loss of gene function; amorphic.
7. (mechanical engineering, of a position or setting) Neutral.
   In normal operation, the input cranks to both the MPCU and standby rudder actuator will rotate to provide the servo valve command to the units, and the rudder will be hydraulically moved by the MPCU. The rudder movement is in turn fed back mechanically to both the MPCU and standby actuator systems so that when the rudder surface deflects to the position commanded by the pilot, the input cranks on both of the units will be returned to their null positions. Thus, there is a geometric relationship between the rudder position, the input crank of the MPCU, the torque tube, and the input crank of the standby rudder actuator that is retained during normal operation. 27 March 2001, National Transportation Safety Board, “1.16.3 Detail Examination and Tests of Standby Rudder Actuator Input Shaft and Bearing”, in Aircraft Accident Report: Uncontrolled Descent and Collision With Terrain, United Airlines Flight 585, Boeing 737-200, N999UA, 4 Miles South of Colorado Springs Municipal Airport, Colorado Springs, Colorado, March 3, 1991, archived from the original on 2022-05-08, pages 62–63

verb

1. (transitive, archaic) To nullify; to annul.
   Thy fair enchanted cup, and warbling charms / No more on me have pow’r, their force is null’d, / So much of Adders wiſdom I have learnt / To fence my ear againſt thy Sorceries. 1671, John Milton, “Samson Agonistes”, in Paradise Regain’d, 5th edition, London: Jacob Tonson, published 1707, page 144
2. To return to the null position, setting, etc.
   Three factors could ameliorate the effect of a bound input shaft and bearing. The first is the elasticity of the control system linkage that, against a definable load, will permit sufficient deformation of the otherwise rigid link feedback loop to null the MPCU servo valve. The second factor is the application of a load sufficient to break loose the binding between the input shaft and bearing. The third factor is a loss of torque of the bearing in the standby rudder actuator housing to permit the rotation of the bearing and shaft together within the housing to compensate for the bound shaft. 27 March 2001, National Transportation Safety Board, “1.16.3 Detail Examination and Tests of Standby Rudder Actuator Input Shaft and Bearing”, in Aircraft Accident Report: Uncontrolled Descent and Collision With Terrain, United Airlines Flight 585, Boeing 737-200, N999UA, 4 Miles South of Colorado Springs Municipal Airport, Colorado Springs, Colorado, March 3, 1991, archived from the original on 2022-05-08, page 63
3. To form nulls, or into nulls, as in a lathe.
4. (computing, slang, transitive) To crack; to remove restrictions or limitations in (software).