Sound sad, vision being cut short (4)
I believe the answer is:
sigh
'sound' is the definition.
(sigh is a kind of sound)
'vision being cut short' is the wordplay.
'vision' becomes 'sight' (synonyms).
'being cut short' means to remove the last letter.
'sight' with its final letter taken away is 'SIGH'.
'sad' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for sigh that I've seen before include "Exhale deeply" , "Audible exhalation of breath" , "Weary exhalation" , "pained expression" , "Exhalation of breath, with relief say" .)