QUANTUM MERUIT (Lat. for "as much as he has deserved "), in the law of contract, originally a form of action on the case, grounded on a promise to pay the plaintiff for work done as much as it was worth. It has been abolished as a special form of action, but the term is still in use where, in cases of special contract, there has been a breach amounting to a discharge by one party before the other party has done all that he was bound to do. In such a case the plaintiff sues for a quantum meruit or the value of so much as he has done.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)