The company was forced to 'declare bankruptcy'. [=to formally say in a legal document that it was bankrupt]
He 'declared' himself the winner. = He 'declared' that he was the winner. = He 'declared victory'.
His 'declared' [=publicly stated] aim/goal/intention is to improve the city's downtown area.
(..) Halt! Goods inspection! Papers, please! Oh, it's you, Bard. Morning, Percy. Anything to declare? Nothing, but that I am cold and tired... ...and ready for home. You and me both. There we are. All in order. (..)2013 The Hobbit: The Desolation of Smaug