Things nearby, ultimately close (6)
I believe the answer is:
stuffy
'ultimately close' is the definition.
'stuffy' can be an answer for 'close' (both can mean uncomfortably warm). I'm not sure about the 'ultimately' bit.
'things nearby' is the wordplay.
'things' becomes 'stuff' (I've seen this in another clue).
'nearby' becomes 'y' (I can't explain this - if you can you should believe this answer much more).
'stuff'+'y'='STUFFY'
Can you help me to learn more?
(Other definitions for stuffy that I've seen before include "Lacking ventilation; narrow-minded" , "needing to be aired" , "Airless - humourless" , "Priggish" , "Badly ventilated" .)