This document provides a chronological overview of definitions for the term "gamification" from 2002 to 2014 from various sources such as websites, books, papers, and magazines. Early definitions in the 2000s focus on applying game mechanics to non-game contexts to increase engagement. Definitions from the 2010s emphasize using game design elements and principles to motivate and engage users for goals like learning, productivity, or customer loyalty. Later definitions distinguish gamification from games and specify it as applying gameful experiences and design to contexts not primarily involving gaming.