Film director joined ranks, heading for immortality (7)
I believe the answer is:
fellini
'film director' is the definition.
(director Federico Fellini)
'joined ranks heading for immortality' is the wordplay.
'joined ranks' becomes 'fellin' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'heading for' says to take the initial letters.
The first letter of 'immortality' is 'i'.
'fellin'+'i'='FELLINI'
Can you help me to learn more?
(Other definitions for fellini that I've seen before include "Federico ------- (1920-1993), Italian film director" , "It. director of Satyricon" , "Italian film-maker, d. 1993" , "Federico --, Italian film producer" , "Shooting Italian" .)