A perpetually discouraging thing to say (5)
I believe the answer is:
never
'discouraging thing to say' is the definition.
I can't tell whether this definition defines the answer.
'a perpetually' is the wordplay.
I cannot really understand how this works, but
'perpetually' could be 'ever' (I've seen this in another clue) and 'ever' is found in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for never that I've seen before include "At no time in the past or future" , "Strong negative" , "No way" , "when pigs fly" , "' - - Say - - Again': Bond film" .)