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?"
The word "yarr" is from my native language, which is called Wesseaslisc. So-called "English pirates" were not English. They were Wesseascynn. Anyway, the word "yarr" means "yes".