Members of artistic movement more than once chucked into ditches (7)
I believe the answer is:
cubists
'members of artistic movement' is the definition.
'more than once chucked into ditches' is the wordplay.
'more than once' becomes 'bis' (musical direction meaning 'play again').
'chucked into' means one lot of letters goes inside another.
'ditches' becomes 'cuts' (cut is a kind of ditch).
'bis' inserted within 'cuts' is 'CUBISTS'.
(Other definitions for cubists that I've seen before include "Painters" , "Disciples of Picasso, perhaps" , "group of artists" .)