Gas inclined to be used around Pennsylvania (7)
I believe the answer is:
propane
'gas' is the definition.
(I know that propane is a type of gas)
'inclined to be used around pennsylvania' is the wordplay.
'inclined' becomes 'prone' (similar in meaning).
'to be used around' is an insertion indicator.
'pennsylvania' becomes 'PA'.
'prone' enclosing 'pa' is 'PROPANE'.
(Other definitions for propane that I've seen before include "Type of gas" , "Gas used as fuel" , "Bottle gas" , "gaseous fuel" , "Bottled fuel gas" .)