In good condition to cover area in short order (4)
I believe the answer is:
fiat
'short order' is the definition.
'fiat' can be an answer for 'order' (I've seen this in another clue). I'm unsure of the 'short' bit.
'in good condition to cover area' is the wordplay.
'in good condition' becomes 'fit' (I've seen this in another clue).
'to cover' means one lot of letters goes inside another.
'area' becomes 'a' (maths abbreviation).
'fit' going around 'a' is 'FIAT'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for fiat that I've seen before include "Command" , "Decree; Italian car make" , "Decree or official permission" , "Let it be done - it's a Latin order" , "Official sanction" .)