null

Short definition from Wiktionary

Noun

1. 1
   A non-existent or empty value or set of values.
2. 2
   Zero quantity of expressions; nothing.
3. 3
   Something that has no force or meaning.
4. 4
   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. 5
   The attribute of an entity that has no valid value.
6. 6
   One of the beads in nulled work.
7. 7
   The null hypothesis.

Adjective

1. 1
   Having no validity; "null and void".
2. 2
   Insignificant.
3. 3
   Absent or non-existent.
4. 4
   Of the null set.
5. 5
   Of or comprising a value of precisely zero.
6. 6
   Causing a complete loss of gene function; amorphic.
7. 7
   Neutral.

Verb

1. 1
   To nullify; to annul.
2. 2
   To return to the null position, setting, etc.
3. 3
   To form nulls, or into nulls, as in a lathe.
4. 4
   To crack; to remove restrictions or limitations in (software).

Proper noun

1. 1
   A surname.