Fifty turn up for record (3)
I believe the answer is:
log
'for record' is the definition.
(logging is a kind of recording)
'fifty turn up' is the wordplay.
'fifty' becomes 'L' (Roman numeral).
'turn' becomes 'go' (a person's move in a board game).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'go' reversed gives 'og'.
'l'+'og'='LOG'
(Other definitions for log that I've seen before include "fuel consumed" , "Written account of a voyage" , "Record book; tree part" , "Lump of wood or ship's diary" , "Official record of events" .)