Keep a record of (3)
I believe the answer is:
log
'keep a record of' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for log that I've seen before include "A ship or plane's diary" , "Chunk of wood" , "Piece of wood - record" , "Formal record" , "Lump of wood or ship's diary" .)