Language course after a do-it-yourself setback (7)
I believe the answer is:
yiddish
'language' is the definition.
(Yiddish is an example)
'course after a do-it-yourself setback' is the wordplay.
'course' becomes 'dish' (dish can mean a course of a meal).
'after' says to put letters next to each other.
'a do-it-yourself' becomes 'diy' (abbreviation for do-it-yourself).
'setback' says the letters should be written backwards.
'diy' written backwards gives 'yid'.
'dish' put after 'yid' is 'YIDDISH'.
(Other definitions for yiddish that I've seen before include "German/Hebrew mixture" , "I did shy away from this language of European Jews" , "Language spoken by Jews" , "European Jews' vernacular" , "Mixed language used by Jews of central and eastern Europe" .)