Collocations for republic - noun

new, young
former
the former Yugoslav republics

autonomous, free, independent, sovereign
breakaway
the breakaway republics of the former Soviet empire

constitutional, democratic, federal, Islamic, people's, secular, socialist
a constitutional republic based on the principles of democracy
the People's Republic of China

banana (disapproving,offensive)

become
the year that Guyana became a socialist republic

build, create, establish, form, found
defend, preserve, save
declare (sth), proclaim (sth)
They have declared themselves an independent democratic republic.

recognize (sth as)
overthrow