Same as "Yar".
An exclamation often heard in relation to a fortuitous recreational drug purchase,or at the onset of an unusually pronounced drug effect.
The origin of this word is indeed to be
found among the high-sea pirates of yore; current usage simply puts it into the mouths of their post-modern-day counterparts.
"Oh,YAR...that stuff'd knock the peachfuzz offa' Thai pirate's chest!"
"Yar,Yar,...sweet deal on the barrel of yaba there mah shabizzler...my ya roi?"