Really old worker outside transport company mid-morning (7)
I believe the answer is:
ancient
'really old' is the definition.
(I've seen this in another clue)
'worker outside transport company mid-morning' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'outside' is an insertion indicator.
'transport company' becomes 'cie' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mid' means to look at the middle letters.
The central letter of 'morning' is 'n'.
'cie'+'n'='cien'
'ant' going around 'cien' is 'ANCIENT'.
Can you help me to learn more?
(Other definitions for ancient that I've seen before include "Antiquated" , "Pistol" , "Dating from long ago" , "Of times long past" , "Nice tan (anag.)" .)