Some fear a chest pain (7)
I believe the answer is:
earache
'pain' is the definition.
(earache is a kind of pain)
'some fear a chest' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'EARACHE' is hidden within 'fear a chest'.
(Other definitions for earache that I've seen before include "Lughole pain" , "Pain for listener" , "Ace hare (anag.)" , "Pain in the hearing organ" , "a problem for some listeners" .)