Lat. He undertook; he promised. A promise or engagement by which one person assumes or undertakes to do some act or pay something to another. It may be either oral or in writing, but is not under seal. It is czrpress if tne promisor puts his engagement in distinct and definite language; it is implied where the law infers a promise (though no formal one has passed) from the conduct of the party or the circumstances of the case.