Doing the non-applicable thing, starting inside, making an offering (8)
I believe the answer is:
donating
'making an offering' is the definition.
I can't tell whether this defines the answer.
'doing the non-applicable thing starting inside' is the wordplay.
'starting' indicates taking the first letters.
'inside' indicates putting letters inside.
The initial letters of 'non applicable thing' is 'nat'.
'doing' enclosing 'nat' is 'DONATING'.
Can you help me to learn more?
(Other definitions for donating that I've seen before include "Giving away - maybe blood" , "Offering a gift" , "I don't nag about giving" , "Giving to charity" .)