Faint-hearted? That's some shot I middled (5)
I believe the answer is:
timid
'faint-hearted?' is the definition.
(I know that faint can be written as timid)
'some shot i middled' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'TIMID' can be found hidden inside 'shot i middled'.
'that's' is the link.
(Other definitions for timid that I've seen before include "Easily alarmed, shy" , "Lacking in courage" , "Lacking self-confidence" , "Diffident, faint-hearted" , "Bashful or fearful" .)