Fat girl appears on time (4)
I believe the answer is:
suet
'fat' is the definition.
(suet is a kind of fat)
'girl appears on time' is the wordplay.
I cannot quite see how this works, but
'girl' could be 'sue' (girl's name) and 'sue' is present in the answer.
'time' could be 't' (abbreviation) and 't' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for suet that I've seen before include "Hard edible fat" , "Hard white fat on sheep's kidneys" , "Hard fat from beef and sheep" , "Solid fat used in cooking" , "Hard fat in cattle and sheep" .)