Surrender legal case about British money (6)
I believe the answer is:
submit
'surrender' is the definition.
(thesaurus)
'legal case about british money' is the wordplay.
'legal case' becomes 'suit'.
'about' means one lot of letters goes inside another.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'money' becomes 'm' (abbreviation in economics).
'b'+'m'='bm'
'suit' going around 'bm' is 'SUBMIT'.
(Other definitions for submit that I've seen before include "Render" , "Yield or refer to another" , "Consent" , "Yield, present (proposal)" , "Give way" .)