Null (adjective)

1. Having no legal or binding force; invalid.
2. Having no value or significance; meaningless.
3. Having no positive qualities; empty; void.
4. Computing: Containing no valid data; having a value of zero or no value at all.

Origin:

From middle english nul, from old french nul, from latin nullus.

Examples:

1. The contract was declared null and void due to a legal technicality.
2. His argument was dismissed as null and without merit.
3. The experiment produced null results, indicating that the hypothesis was incorrect.
4. The defendant's claims were nullified by the overwhelming evidence against him.
5. The variable was set to null to avoid errors in the code.