term:

Repudiate

repudiate vt

-at·ed
-at·ing
: to disavow or reject an obligation (as a debt) or duty (as performance under a contract)
;specif
: to indicate an inability or unwillingness to perform as promised under (a contract)
re·pu·di·a·tor [-ā-tər]
n

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.