repudiate

Concise Oxford English Dictionary © 2008 Oxford University Press:
repudiate /rɪˈpjuːdɪeɪt/

▶verb

• 1 refuse to accept or be associated with.

• 2 deny the truth or validity of.

• 3 chiefly Law refuse to fulfil or discharge (an agreement, obligation, or debt).

• 4 archaic disown or divorce (one's wife).

– derivatives
repudiation noun,
repudiator noun,
repudiatory /rɪˈpjuːdɪəˌt(ə)ri/ adjective (Law).

– origin ME (orig. an adj. in the sense ‘divorced’): from L. repudiatus ‘divorced, cast off’, from repudium ‘divorce’.