Film Charlie climbing ridge with others (2,6)
I believe the answer is:
et cetera
'with others' is the definition.
'film charlie climbing ridge' is the wordplay.
'film' becomes 'ET'.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'climbing' says the letters should be written in reverse (in a down clue, letters climb up).
'ridge' becomes 'arete' (arete is a kind of ridge).
'arete' backwards is 'etera'.
'et'+'c'+'etera'='ET CETERA'
(Other definitions for et cetera that I've seen before include "Drive out, expel" , "something similar" , "Etc" , "Including other similar items" , "And the rest (Latin)" .)