Old two-shilling piece (6)
I believe the answer is:
florin
'old two-shilling piece' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for florin that I've seen before include "Old British (or Dutch) coin" , "old currency" , "Old 2-shilling piece" , "Former British silver coin" , "Old 2-shilling coin" .)