Someone which causes sexual arousal or masturbatory desire. A person can become, or stop being, a source at any given time. From 'Curb Your Enthusiasm.'

One who has a mania for music.

1. Unreliable, unverified, phantom person(s) or entity. Often cited by the media to publish a story that they don't want to do the legwork to find physical evidence for.

2. The thing that is always missing from online rants, is never given when asked for, and that is always discredited the moment it is posted.

It is another word for retard(short for resource)

Source is an extremely flexible/powerful video game engine developed by Valve Software, and it's primary use is for Half-Life 2, Counter-Strike: Source, and many Half-Life mods. But other games such as Vampires - Masqeurade: Bloodlines uses the same engine. It took Valve over 5 years of solid programming to develop Source.

To buy. To find. To acquire. To get.
Its current usage follows the modern fashion of using a noun as a verb.

Where something comes from. Commonly refers to source code, which is where applications come from.