Rush to expel German? Yes (4)
I believe the answer is:
sure
'yes' is the definition.
(thesaurus)
'rush to expel german?' is the wordplay.
'rush' becomes 'surge' ('surge' can be a synonym of 'rush').
'to expel' is a deletion indicator.
'german?' becomes 'g' (abbreviation).
'surge' with 'g' taken out is 'SURE'.
(Other definitions for sure that I've seen before include "Definite" , "certainly in the USA" , "Completely certain" , "of course" , "Safe" .)