Gamefi is a fusion of Play To Earn blockchain games & Decentralized finance(DeFi). It essentially refers to the monetization of gaming via the Play-to-earn model such that players can extract income and win rewards as NFTs, tokens, and cryptocurrencies. This new concept of gaming has enabled frameworks for player-as-owners rather than the standard player-as-consumers
I have included here Move To Earn because i think it belongs in the GameFi category.