incitement of discontent or rebellion against a government.

any action, esp. in speech or writing, promoting such discontent or rebellion.

Archaic . rebellious disorder.

noun

agitation , defiance , disobedience , dissent , insubordination , insurgence , insurgency , insurrection , mutiny , revolt , revolution , treason , uprising , seditiousness , traitorousness , coup , dissension , lawlessness , protest , rebellion , riot , strife , subversion