a person highly skilled in the use of a gun and a veteran of many gunfights, especially one living during the frontier days of the American West.

A person of homosexual persuasion

gun·fight
noun /ˈgənˌfīt/

1. A game popular with children in suburban areas in which a minimum of 2 players on 2 teams hurl rocks at each other whilst attempting to find shelter behind objects such as bushes or cars

a poser, combat veteran wannabe. AKA playstation commando, or basement ninja. SOmebody who plays too many video games and thinks that they are a weapons expert. When out of the basement, they can be found spreading misinformation about weapons based on the "information menu" on the game's weapon's menu. They are easy to spot, and use terms like ".308 Lapua Magnum" or they insist that a 9mm will shoot through a block wall.
Generally the closest these generally harmless folk come to actually shooting a real gun is the gun's AIRSOFT counterpart.
They have no idea what firearms safety is, have never read the "10 Commandments of Range Safety, and when they reach 21, the first thing they buy is a Glock 19 with a laser. They are often suprised that the laser is an aiming device, not a guidance system for the bullet.
When corrected, their reactions can be anything from mild embarrassment to a militant rage.
Fun to watch at gunshows when they fondle a real gun and are amazed that it is so heavy.

done like a western gunfight, 2 gay men stand back to back and when one says "JERK" they proceed to turn around and masturbate on eachother. the first to ejaculate on his opponent is the winner

The Mexican Gunfight is a shot-glass cocktail loaded with equal parts 291 Colorado Whiskey and Casamigos Mezcal

Alternative use:

If you make with subpar whiskey and/or subpar mezcal it's called: a Mexican Hooker Gun Fight, a Mexican Shank Fight, a Rusty Shank Fight -- Either way, you lose!

The act of taking an amount of any substance to a gathering which is obviously insufficient.