Big tank's entry crushing several with Resistance (9)
I believe the answer is:
gasometer
'big tank's' is the definition.
'gasometer' can be an answer for 'tank's' (gasometer is a kind of tank). I'm not sure about the 'big' bit.
'entry crushing several with resistance' is the wordplay.
I cannot really see how this works, but
'several' could be 'some' (similar in meaning) and 'some' is found within the answer.
'entry' could be 'gate' (I've seen this in another clue) and 'gate' is found within the remaining letters.
'resistance' could be 'r' (electronics abbreviation) and 'r' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gasometer that I've seen before include "could be seen by the Oval" , "Fuel storage tank" , "Game store (anag) - fuel store" , "source of fuel" , "Large fuel tank" .)