Penny, eg (4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">penny eg</span>' is the definition.<br/ ><span class="explanation-format__explanation">(penny is a kind of coin)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for coin that I've seen before include "little money" , "Mint" , "Metal piece of money" , "Money; devise (a word)" , "Metal currency" .)
(Other definitions for copper that I've seen before include "Atomic number 29" , "An element; small coin" , "bluebottle" , "Ductile metal" , "Low-value coin" .)