Add revenue fraudulently, accepting zero made an effort (11)
I believe the answer is:
endeavoured
'made an effort' is the definition.
The definition and answer can be both to do with social activities as well as being past participle verbs.
Maybe they are linked in a way I don't understand?
'add revenue fraudulently accepting zero' is the wordplay.
'fraudulently' indicates anagramming the letters (a fraudulent version of the letters).
'accepting' means one lot of letters goes inside another (inserted letters are accepted).
'zero' becomes 'O' (O resembles 0).
'add'+'revenue'='addrevenue'
'addrevenue' with letters rearranged gives 'endeavured'.
'endeavured' enclosing 'o' is 'ENDEAVOURED'.
Can you help me to learn more?
(Other definitions for endeavoured that I've seen before include "Being tried" , "Attempted" .)