Southern California surfer slang, mean big, huge, heavy.
As a verb, to Herk something means to lift a very heavy object. As an adverb, Herky means heavy, cumbersome.
From Hercules or Herculean.
âDude, that was a herkin huge wave man. I had to bail.â
âMan, I had to herk that suitcase up those stairs.â
âYou, lift that boulder, man. It's too herky for me.â