Aztec Camera finally haunt fans with line (7)
I believe the answer is:
nahuatl
'aztec' is the definition.
(I've seen this before)
'camera finally haunt fans with line' is the wordplay.
'finally' says to take the final letters.
'fans with' indicates anagramming the letters (I've seen 'fanned' mean this (I've seen this in other clues)).
'line' becomes 'l' (used when specifying particular lines from a poem).
The final letter of 'camera' is 'a'.
'a'+'haunt'='ahaunt'
'ahaunt' with its letters anagrammed with 'l' can make 'NAHUATL'.
(Other definitions for nahuatl that I've seen before include "Language of southern Mexico and Central America" , "Aztec" , "Mexican native language" .)