Cheers advanced ability (6)
I believe the answer is:
talent
'ability' is the definition.
(a talent is an ability)
'cheers advanced' is the wordplay.
'cheers' becomes 'ta' (both can informally mean thank you).
'advanced' becomes 'lent' (advance can mean to lend).
'ta'+'lent'='TALENT'
(Other definitions for talent that I've seen before include "ancient currency" , "Innate skill" , "Skill, natural ability" , "that some scouts try to find" , "some scouts are looking for" .)