Define Null and Void. Null and Void synonyms, Null and Void pronunciation, Null and Void translation, English dictionary definition of Null and Void. adj. 1. Having no legal force; invalid: render a contract null and void. One void contract example is a contract that involves illegal behaviors, such as criminal activity or gambling. If you enter into a contract to kill another person, that is a void contract, because you cannot contract to do something illegal. Another example of a void contract is one that is entered into by a person suffering from a mental A void contract cannot be enforced by law. Void contracts are different from voidable contracts, which are contracts that may be nullified. However, when a contract is being written and signed, there is no automatic mechanism available in every situation that can be utilized to detect the validity or enforceability of that contract.