Card sharp versus card shark

[Douglas G. Wilson]

>Is there a connection between this "shirk" or "shark" and the gambler as
>"shark" or "sharp"?

I believe there probably is. At least "shark[er]" and "shirk[er]" in the
senses "gambler/swindler/parasite/etc." seem to reflect the same German
word (apparently "schork" or so, = modern "Schurke" = "rogue" or so, I
think) [OED presents this connection]. "Sharp[er]" is very similar; its
exact relationship to "shark[er]" is uncertain, AFAIK.

-- Doug Wilson