Block quips about British anticlimax (4,5)
I believe the answer is:
damp squib
'anticlimax' is the definition.
(I've seen this before)
'block quips about british' is the wordplay.
'block' becomes 'dam' (damming is a kind of blocking).
'about' is an anagram indicator.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'quips' with letters rearranged gives 'psqui'.
'dam'+'psqui'+'b'='DAMP SQUIB'
(Other definitions for damp squib that I've seen before include "Firework that doesn't" , "Let-down" , "Moist explosive for failed attempt" , "Something less impressive than expected" , "set up by a guy?" .)