A public, non-violent and conscientious breach of law undertaken to bring about a change in laws or government policy, usually with willingness to accept the legal consequences.
In more detail
The term is widely credited to Henry David Thoreau, who refused to pay a poll tax in protest at slavery and the war with Mexico. On the account associated with Rawls, civil disobedience occurs at the boundary of fidelity to law by those who generally respect their regime. Scholars dispute whether it must be non-violent and whether it can be justified in non-ideal democracies.