Gratuitous. Gratuitous describes an act not involving consideration, compensation, or return benefit. In contract law, a gratuitous promise -- a promise made without an expectation of a return benefit or burden on the promisee -- may be unenforceable if the promisor fails to do what he promised.
If you need help with defining a legal word or phrase, check out FindLaw's Legal Dictionary for free access to more than 8,000 definitions of legal terms. Or check back here next Sunday, when Legalese From A to Z will demystify five more legal terms you may not know, beginning with the letter "H."