Some bozo needing gas (5)
I believe the answer is:
ozone
'gas' is the definition.
(I've seen this before)
'some bozo needing' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'OZONE' is hidden in the letters of 'bozo needing'.
(Other definitions for ozone that I've seen before include "Kind of oxygen layer in atmosphere, has hole in it" , "It's said to brace" , "Toxic form of oxygen" , "That precious layer" , "Sea air; bleaching agent" .)