Moggy approximately on time (3)
I believe the answer is:
cat
'moggy' is the definition.
(I've seen this before)
'approximately on time' is the wordplay.
'approximately' becomes 'ca' (abbreviation for circa).
'on' says to put letters next to each other.
'time' becomes 't' (abbreviation).
'ca'+'t'='CAT'
(Other definitions for cat that I've seen before include "Grimalkin" , "A tom" , "Malicious gossip" , "An old whip with nine tails" , "Animal (domesticated or wild)" .)