Nail finally puncturing immense spare tyre? (4)
I believe the answer is:
flab
'spare tyre?' is the definition.
(I've seen this before)
'nail finally puncturing immense' is the wordplay.
'finally' says to take the final letters.
'puncturing' means one lot of letters goes inside another (I've seen this in other clues).
'immense' becomes 'fab' (I can't justify this - if you can you should give a lot more credence to this answer).
The final letter of 'nail' is 'l'.
'l' put inside 'fab' is 'FLAB'.
Can you help me to learn more?
(Other definitions for flab that I've seen before include "Soft loose flesh" , "Loose body fat" , "Unwanted body fat" , "Sign of over-indulgence" , "Informally, unsightly fat" .)