A channel showing film for all the family? That's rather unusual (7)
I believe the answer is:
urethra
'a channel' is the definition.
(urethra is a kind of channel)
'film for all the family? that's rather unusual' is the wordplay.
'film for all the family?' becomes 'u' (British film grading).
'that's' means one lot of letters go next to another.
'unusual' indicates anagramming the letters.
'rather' is an anagram of 'rethra'.
'u'+'rethra'='URETHRA'
'showing' acts as a link.
(Other definitions for urethra that I've seen before include "course of discharge" , "wee channel" , "part of body" , "Canal from the bladder" .)