Allow that you give your seat up to (5,3)
I believe the answer is:
stand for
'allow that you give your seat up to' is the definition.
'stand for' can be an answer for 'allow' (I've seen this in another clue). I'm not certain of the rest of the definition.
'allow that you give your seat up to' is the wordplay.
I cannot really see how this works, but
'allow' could be 'stand' (standing is a kind of allowing) and 'stand' is present in the answer.
'to' could be 'for' and 'for' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for stand for that I've seen before include "champion" , "Signify" , "Represent while on feet?" , "brook" , "become a substitute" .)