Fish used as currency in medieval England (3)
I believe the answer is:
eel
(Other definitions for eel that I've seen before include "Slippery person" , "Slippery creature" , "slipper" , "Unagi, in a sushi bar" , "Evasive type" .)
I believe the answer is:
eel
(Other definitions for eel that I've seen before include "Slippery person" , "Slippery creature" , "slipper" , "Unagi, in a sushi bar" , "Evasive type" .)