Do second language, start with German (7)
I believe the answer is:
shindig
'do' is the definition.
(I've seen this before)
'second language start with german' is the wordplay.
'second' becomes 's' (common abbreviation).
'language' becomes 'hindi' (Hindi is an example).
'start with' indicates taking the first letters.
The initial letter of 'german' is 'g'.
's'+'hindi'+'g'='SHINDIG'
(Other definitions for shindig that I've seen before include "commotion" , "Big lively party (colloq.)" , "Lively celebration (informal)" , "Noisy disturbance" , "Rumpus" .)