Gas bubble area (5)
I believe the answer is:
ozone
'gas bubble area' is the definition.
'ozone' can be an answer for 'gas' (I've seen this before). I'm not sure about the 'bubble area' bit.
'gas bubble area' is the wordplay.
I cannot really understand how this works, but
'gas' could be 'o' (chemical symbol for oxygen) and 'o' is found in the answer.
'area' could be 'zone' (zone is a kind of area) and 'zone' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ozone that I've seen before include "Form of atmospheric oxygen" , "A gas; threatened layer in air" , "Condensed oxygen; sea air" , "(Depleted) layer of gas" , "bracing atmosphere" .)