Mate in airfield is in a race-car type of word (10)
I believe the answer is:
palindrome
'type of word' is the definition.
(I know that palindrome is a type of word)
'mate in airfield' is the wordplay.
'mate' becomes 'pal' (both can mean a friend).
'airfield' becomes 'drome' (I can't explain this - if you can you should believe this answer much more).
'pal'+'in'+'drome'='PALINDROME'
'is in a race-car' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for palindrome that I've seen before include ""Mr Owl ate my metal worm", for example" , "Mum, perhaps" , "E.g. mum, dad" , "madam, perhaps" , "Word like the Indian language "Malayalam", for instance" .)