Point to a broken seat you can't properly use (5)
I believe the answer is:
waste
'use' is the definition.
(wasting is a kind of using)
'point to a broken seat' is the wordplay.
'point' becomes 'w' (W is an example).
'to a broken' indicates an anagram.
'seat' anagrammed gives 'aste'.
'w'+'aste'='WASTE'
'you can't properly' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for waste that I've seen before include "Refuse, garbage, rubbish" , "desert" , "Misuse" , "Become gradually weaker" , "Useless leftovers" .)