An ability or skill (6)
I believe the answer is:
talent
I believe this is a double definition.
'an ability' is the first definition.
(a talent is an ability)
'skill' is the second definition.
(talent can mean a skill or ability)
(Other definitions for talent that I've seen before include "Gift - aptitude" , "Special or very great ability" , "Attractive young girls" , "Biblical coin" , "Natural ability or flair" .)