Language changed at canal (7)
I believe the answer is:
catalan
'language' is the definition.
(Catalan is an example)
'changed at canal' is the wordplay.
'changed' indicates anagramming the letters.
'at'+'canal'='atcanal'
'atcanal' is an anagram of 'CATALAN'.
(Other definitions for catalan that I've seen before include "from part of Spain" , "Of NE Spanish region" , "Native of NE Spain area" , "Native of northeast Spain" , "Language of Spanish region" .)