officious bystander testofficious bystander test: part of the legal test applied by ...: part of the legal test applied by courts in contract law disputes to determine whether a term should be implied into a contract, even though that term was not written into the contract expressly; if the hypothetical officious bystander suggested to the contracting parties that a particular term be included in the contract and ‘they would testily suppress him with a common ‘oh of course’, that term can be implied into the contract.