Persian say approximately on time (3)
I believe the answer is:
cat
'persian say' is the definition.
(I've seen this in another clue)
'approximately on time' is the wordplay.
'approximately' becomes 'ca' (abbreviation for circa).
'on' means one lot of letters go next to another.
'time' becomes 't' (abbreviation).
'ca'+'t'='CAT'
(Other definitions for cat that I've seen before include "Lash < jazz fan" , "Grimalkin" , "Tabby" , "An old whip with nine tails" , "Animal - one with nine tails!" .)