Iffy film from the 1970s (5)

I believe the answer is:

rocky

This clue is a double definition.

'iffy' is the first definition.
(thesaurus)

'film from the 1970s' is the second definition.

(Other definitions for rocky that I've seen before include "Craggy; difficult" , "Unsteady, unstable" , "Unstable - full of crags" , "'-' Marciano, US boxer" , "Shaky; some Mountains" .)

I've seen this clue in The Telegraph.

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