Ballpoint pen (4)
I believe the answer is:
biro
'ballpoint pen' is the definition.
(synonyms)
This is all the clue.
(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" .)