State can unite state with state border (9)

I believe the answer is:

enunciate

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'state' is the definition.
(I know that enunciate is a type of state)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for enunciate that I've seen before include "State clearly or formally" , "Speak with precision" , "Articulate" , "Utter" , "Pronounce words clearly" .)

I've seen this clue in the Sydney Morning Herald.

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