Said to be an immoral end (4)
I believe the answer is:
oral
'said' is the definition.
(both can mean spoken)
'be an immoral end' is the wordplay.
'ORAL' is hidden within the letters.
However, I am uncertain how this is indicated.
'to' is the link.
Can you help me to learn more?
(Other definitions for oral that I've seen before include "'Spoken, not written (4)'" , "Vocal test" , "Mouth-related" , "Via the mouth" , "Kind of examination" .)