Definition from Wiktionary, the free dictionary
A leaves for vacation for two weeks during the summer. B mows A's lawn. B requests payment for this service. Under common law doctrine B is not entitled to any payment from A beyond whatever A cares to give.
- (law) A person who voluntarily, and without request or pre-existing legal duty, interjects himself/herself into the affairs of another, then seeks remuneration for services or reimbursement.
- Second Restatement of Contracts Sec. 74
- Black's Law Dictionary