Painless; easy (10)
I believe the answer is:
effortless
I believe this clue is a double definition.
'painless' is the first definition.
(thesaurus)
'easy' is the second definition.
(similar in meaning)
(Other definitions for effortless that I've seen before include "Requiring no physical or mental exertion" , "a breeze?" , "easy" , "Not showing any strain" .)