1. Noun. an effect applied to a character that enhances its abilities. Buffs are usually temporary effects gained through the use of permanent abilities, which makes them distinct from power-ups which are usually the result of found items. The opposite of this definition is "debuff." 2. Verb. To give someone/something a buff. 3. Verb. A meta-game term to refer to the act of game developers releasing a patch that enhances a given ability or stat. The opposite of nerf.