Gratification, n.
Etymology: [L. gratificatio: cf. F. gratification.]
1. The act of gratifying, or pleasing, either the mind, the taste, or the appetite; as, the gratification of the palate, of the appetites, of the senses, of the desires, of the heart.
2. That which affords pleasure; satisfaction; enjoyment; fruition: delight.
3. A reward; a recompense; a gratuity. Bp. Morton.
Shades of meaning
Fernald has no entry of its own for gratification; he lists it under happiness.
Where he writes about it:
Gratification is the giving any mental or physical desire something that it craves; satisfaction is the giving such a desire all that it craves. — from happiness
Happiness is the positively agreeable experience that springs from the possession of good, the gratification or satisfaction of the desires or the relief from pain and evil. — from happiness
As referring to a mental state, gratification is used to denote a mild form of happiness resulting from some incident not of very great importance; satisfaction should properly express a happiness deeper, more complete, and more abiding; but as intellect or sensibilities of a low order may find satisfaction in that which is very poor or unworthy, the word has come to be feeble and tame in ordinary use. — from happiness
Happiness, in the full sense, is mental or spiritual or both, and is viewed as resulting from some worthy gratification or satisfaction; we may speak of a brute as experiencing comfort or pleasure, but scarcely as in possession of happiness; we speak of vicious pleasure, delight, or joy, but not of vicious happiness. — from happiness