Language used by son attending good, noisy party (7)
I believe the answer is:
shindig
'noisy party' is the definition.
(I've seen this before)
'language used by son attending good' is the wordplay.
'language' becomes 'hindi' (Hindi is an example**).
'used by' means one lot of letters go next to another.
'son' becomes 's'.
'attending' means one lot of letters go next to another.
'good' becomes 'g' (abbreviation).
'hindi' put after 's' is 'shindi'.
'shindi'+'g'='SHINDIG'
(Other definitions for shindig that I've seen before include "Hooley" , "commotion" , "wild party" , "Hidings (anag) - party" , "Lively party, knees-up" .)