Gratification was a feeling of pleasure or satisfaction that resulted from achieving a goal or fulfilling a desire.
In 2152, when T'Pol wished to stay aboard Enterprise NX-01, saying she found the work gratifying, Soval countered that "Gratification is an emotional indulgence." (ENT: "Cease Fire")
In 2268, Captain James T. Kirk offered to have Elaan's guest quarters filled with breakable objects if it would gratify her. (TOS: "Elaan of Troyius")
In 2365, while discussing the Pakled, Deanna Troi said, "They are unwilling to wait for the timely evolution of their species' intellectual capacity. They want instant knowledge, instant power and gratification." (TNG: "Samaritan Snare")
In 2374, Larell praised Quark for being willing to wait for oo-mox, saying "Most men don't know how to defer gratification.". (DS9: "Who Mourns for Morn?")