What does "gratify" mean?

Gratify: To requite; to recompense. [Obs.] It remains . . . To gratify his noble service. Shak. -- To Gratify, Indulge, Humor. Gratify, is the generic term, and has reference simply to the pleasure communicated. To indulge a person implies that we concede something to his wishes or his weaknesses which he could not claim, and which had better, perhaps, be spared. To humor is to adapt ourselves to the varying moods, and, perhaps, caprices, of others. We gratify a child by showing him the sights of a large city; we indulge him in some extra expense on such an occasion; we humor him when he is tired and exacting.