Old cabs provided reversed over a wide area (7)

I believe the answer is:

fiacres

I'm a little stuck... Click here to teach me more about this clue!

'old cabs' is the definition.
(fiacre is a historical type of carriage)

'provided reversed over a wide area' is the wordplay.
'provided' becomes 'if' (eg 'provided it's sunny' means 'if it's sunny').
'reversed' is a reversal indicator.
'over a wide area' becomes 'acres' (I can't justify this - if you can you should give a lot more credence to this answer).
'if' in reverse letter order is 'fi'.
'fi'+'acres'='FIACRES'

Can you help me to learn more?

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.