Get a letter read out (3)
I believe the answer is:
see
'get' is the definition.
(I've seen this before)
'a letter read out' is the wordplay.
'a letter' becomes 'c'.
'read out' indicates a 'sounds like' (homophone) clue.
'c' sounds like 'SEE'.
(Other definitions for see that I've seen before include "Experience" , "Perceive; meet (someone)" , "Bishop's responsibility; observe" , "Glimpse; get" , "Chelmsford" .)