Appropriate European base (7)
I believe the answer is:
germane
'appropriate' is the definition.
(thesaurus)
'european base' is the wordplay.
I cannot quite see how this works, but
'european' could be 'german' (German is an example) and 'german' is present in the answer.
'base' could be 'e' (I've seen this in other clues) and 'e' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for germane that I've seen before include "closely related" , "Relevant to current topic" , "apt" , "Relevant - appropriate" , "Relevant (to subject)" .)