Definition of sharpies:
(n) :
A Sharpie or other brand of felt-tipped marker pen.
(n) :
(colloquial) An alert person.
(n) :
(US, regional) A knowledgeable fisherman.
(n) :
(US) A swindler.
(n) :
(US) A long, narrow fishing boat used in shallow waters.
(n) :
(Australia) A member of a violent, fashionably dressed youth gang of the 1960s and 1970s.