One pound sterling (4)
I believe the answer is:
quid
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one pound sterling</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for quid that I've seen before include "One pound sterling" , "Pound - lump of chewing tobacco" , "something to chew" , "Wad of chewing tobacco" , "that's chewed" .)