Victor discovered Odeon is screening films (6)
I believe the answer is:
videos
'films' is the definition.
(I've seen this before)
'victor discovered odeon is screening' is the wordplay.
'victor' becomes 'V' (phonetic alphabet: alpha, bravo, charlie etc.).
'discovered' says to take the centre (dis-covered - outer letters removed).
'screening' means one lot of letters goes inside another (inserted letters are covered or screened by others).
The middle letters of 'odeon' are 'deo'.
'deo' inserted within 'is' is 'ideos'.
'v'+'ideos'='VIDEOS'
(Other definitions for videos that I've seen before include "movies like these" , "Film copies for home viewing, rent or buy" , "films" , "Recordings of visual images" , "Records" .)