Top class part with hot centre providing ventilation (7)
I believe the answer is:
airhole
'ventilation' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'top class part with hot centre' is the wordplay.
'top class' becomes 'AI' (resembles Ah, old-fashioned term meaning excellent).
'part' becomes 're' (re is a kind of part).
'with' means one lot of letters goes inside another.
'hot centre' becomes 'hol' (I can't justify this - if you can you should give a lot more credence to this answer).
're' placed around 'hol' is 'rhole'.
'ai'+'rhole'='AIRHOLE'
'providing' acts as a link.
Can you help me to learn more?
(Other definitions for airhole that I've seen before include "may avoid suffocation" , "breather?" , "vent" .)