quantum meruit Syllabification: (quan·tum me·ru·it)Pronunciation: /ˌkwäntəm ˈmero͞oit/Definition of quantum meruit noun [usually as modifier] Law a reasonable sum of money to be paid for services rendered or work done when the amount due is not stipulated in a legally enforceable contract. Origin:Latin, literally 'as much as he has deserved'quantum meruit in other Oxford dictionaries Definition of quantum meruit in the British & World English dictionary