Dayton's state (4)
I believe the answer is:
ohio
'dayton's state' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ohio that I've seen before include "American state, capital Columbus" , "US state, joined in 1803" , "State of east central US" , "One of the American states" , "Turning engine part" .)