You searched for: “null
1. A quantity of no importance or amounting to nothing in terms of context or character.
2. Of no consequence, effect, or value; insignificant, and relating to or equal to zero.
3. Amounting to nothing; being absent or nonexistent: "Her efforts had a null result."
4. Etymology: from Middle French (about 1400 to about 1600 A.D.) nul, from Latin nullus, "not any, none"; from ne-, "not, no" + illus, "any".
This entry is located in the following unit: nul-, null-, nulli- + (page 1)
(Latin: not one, not any, none, nothing)
Word Entries containing the term: “null
null and void
1. No longer valid.
2. Having no force, binding power, or validity.
3. Invalid, unenforceable, having no legal force or effect.
4. Without value, effect, consequence, or significance.
5. Being or amounting to nothing; nil; lacking; nonexistent.
This entry is located in the following units: nul-, null-, nulli- + (page 1) Pleonasms or Tautological Redundancies (page 15)
null spot
Area in the reader field that doesn't receive radio waves.

This is essentially the reader's blind spot. It is a phenomenon common to UHF systems.