A Greek character joins blokes in scheduled recreation (9)
I believe the answer is:
'recreation' is the definition.
(amusement is a kind of recreation)
'a greek character joins blokes in scheduled' is the wordplay.
'a greek character joins' becomes 'amu' (I can't justify this - if you can you should give a lot more credence to this answer).
'blokes' becomes 'men' (I've seen this in another clue).
'in' means one lot of letters goes inside another.
'scheduled' becomes 'set' (scheduling something is setting a time for it).
'men' going into 'set' is 'sement'.
Can you help me to learn more?
(Other definitions for amusement that I've seen before include "Diversion, recreation" , "set up through arcade?" , "Interest" , "Pleasant diversion by mute means (9)" , "Something which entertains" .)