British twice blocking government showing evidence of collapse (6)
I believe the answer is:
rubble
'evidence of collapse' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'british twice blocking government' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'twice' shows that letters should be duplicated.
'blocking' means one lot of letters goes inside another (to block can mean to plug a gap in something).
'government' becomes 'rule' (rule can mean government or control).
'b' duplicated is 'bb'.
'bb' placed inside 'rule' is 'RUBBLE'.
'showing' acts as a link.
Can you help me to learn more?
(Other definitions for rubble that I've seen before include "Waste fragments of stone or rock, debris" , "Light theatrical show" , "Debris left after building or demolition" , "Lose stones" , "Demolition site debris" .)