Someone who is totally into cars and is very knowledgeable about how to modify and fix them.

A person who is into all things motorized. This can be cars, motorcycles, machines, planes, or boats, but specifically relating to the engine and power delivery. Knowing how to weld and machine metal are also traits of a gearhead.

A mens shampoo available in quart of oil bottles.

A person with a significant excitement or fetish in leather clothing and/or accessories. Most commonly applied to a homosexual male. Leather clothing and/or accessories are often referred to as "gear".

(n.) Someone who collects the latest, coolest, most efficient, and technologically advanced gadgets for their sport, interest, or hobby.

Someone who smokes/shoots heroin.

Someone who is into, collects, or has a fetish for sports gear , sport uniforms, protective gear, etc (scuba gear, SWAT, football uniforms, motorcross gear, hockey pads, lacrosse, soccer, fighter pilot, etc).