Ballpoint pen (4)
I believe the answer is:
biro
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ballpoint pen</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for biro that I've seen before include "Type of ballpoint pen" , "Pocket item" , "Laszlo Jozsef -, ballpoint pen inventor" , "Writing implement" , "Lazlo -, ballpoint pen inventor" .)