The act of making something worse or weaker.

The verb form of "nerf."
So I don't win too much, I'm nerfing my performance to balance the game.
by sarroth July 1, 2011
Nerfing is a gay term used by receivers.

Usually used to represent their love of receiving anal sex.
'I need a good nerfing' 'I can't wait for that big black man to start Nerfing me later'
by Goldenchild February 11, 2016
The act of masturbating with a Fleshlight or pocket pussy while wearing a condom. Safer sex cannot be had.
In an attempt to increase my sensitivity, I practiced the night before by nerfing with a Fleshlight and a Durex
by AlSipsclar December 17, 2013
Typically applied to online regularly-changed/updated video games.

To "nerf" something means to reduce its 'power' or effectiveness within the game. Often times this is to solve some problem in the game (such as an 'overpowered' weapon/ability or super effective strategy), or to push the players in one direction or another (such as a new cosmetic/item/character).

Nerfs affect the 'meta' or prevailing strategy/characters/items used to win the game. In this way nerfs also give control to the developer of how the players play the game. i.e. nerfing a commonly used item to discourage the community from playing with it.

Some nerfs can be so drastic they change the very fundamentals of the game, and are often a contributing factor to the size of the playerbase, for good or bad.

Outside of games, this would again mean to reduce the things 'power' or 'effectiveness'. The exact analogy that gave birth to this term, is that of a Nerf Gun, compared to a real gun.
Oh man, they totally nerfed 'Titans Armor'! Guess I'll stop playing Golem now :/

They nerfed Irelia again?? Oh wait, its actually a buff. <-- (opposite of nerf)

Great, so now all the free-2-play guns are nerfed, guess I have to buy some to keep competitive. :(
by xX_The_Dank_One_Xx420blazit69 September 25, 2018
The term "nerfing" comes from the online gaming world of Ultima Online.

At one point in the game, the developers reduced the power of swords in melee combat.

This resulted in players complaining that it was like they were hitting each other with nerf bats, not swords.

From then on, if ever something gets made less worth while than it had been originally, it is considered 'nerfed'
"Oh man, they reduced the dmg on the berserker class and now it's totally nerfed!"

"Damn, the Devs nerfed those axe's real good!"
by Dave Elliott January 11, 2005
To make worse or weaken, usually in the context of weakening something in order to balance out a game.
Why the hell did Blizzard nerf Marines' attack damage?
by Koopa January 3, 2003
In the game Overwatch when D.va uses her ultimate ability.
I was stuck in Zarya's ultimate and I heard "Nerf this" and I was suddenly dead.
by Bestdankboi February 26, 2017