A terrible one, say? (5)
I believe the answer is:
state
'one say?' is the definition.
(say is a kind of state)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for state that I've seen before include "Speak" , "Public" , "Country; aver" , "eg Maine" , "Pomp; nation" .)