Adj) Something that gives you a rush. (most commonly used when referring to music)
Adj) Something beautiful or breath taking beyond comprehension.
Etymology: Originating in the deep Melbournian underground culture and coming from the latin word "peaker", defined as one who takes ecstasy, the word was originally used as a way to describe music that caused an adrenaline rush in the listener, likened to the way ecstasy users feel when they take ecstasy. Now days, "peaker-as" is used more loosely as term to describe any thing "cool" or "beautiful"