Some wear a cheerful smile in affliction (7)
I believe the answer is:
earache
'affliction' is the definition.
'some wear a cheerful smile' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'EARACHE' can be found hidden inside 'wear a cheerful smile'.
'in' is the link.
(Other definitions for earache that I've seen before include "listener's discomfort" , "Ace hare (anag.)" , "Pain in an aural appendage" , "a problem for some listeners" , "Pain for listener" .)