Expert, able (7)
I believe the answer is:
skilful
This clue is a double definition.
'expert' is the first definition.
(I know that expert can be written as skilful)
'able' is the second definition.
(thesaurus)
(Other definitions for skilful that I've seen before include "Very adept and proficient" , "'Expert, proficient (7)'" , "Capable" , "exhibiting crafts" , "7 [CLEVER]" .)