Even question adult entering rising river (7)
I believe the answer is:
equable
'even' is the definition.
(thesaurus)
'question adult entering rising river' is the wordplay.
'question' becomes 'qu' (abbreviation).
'adult' becomes 'a' (abbreviation).
'entering' is an insertion indicator.
'rising' says the letters should be written in reverse (going up in a down clue).
'river' becomes 'elbe' (river in Germany).
'elbe' back-to-front is 'eble'.
'qu'+'a'='qua'
'qua' going into 'eble' is 'EQUABLE'.
(Other definitions for equable that I've seen before include "Not easily angered" , "Good-natured" , "not easily rattled" , "Uniform - even" , "Not extreme" .)