1) Prohibition 
• (n.) The act of disallowing; refusal to admit or permit; rejection.
When a payer declines to pay for all or part of a claim submitted for payment. 
A power given to the federal government in the Constitution Act, 1867, under which the cabinet can nullify any provincial law, even though it has received royal assent from the lieutenant-governor of the province.
Dis`al·low'ance noun The act of disallowing; refusal to admit or permit; rejection. Syn. -- Disapprobation; prohibition; condemnation; censure; rejection.
A finding by the IRS after an audit that a business or individual taxpayer was not entitled to a deduction or other tax benefit claimed on a tax return.
the vetoing of delegated legislation by either house of the Parliament, which has the effect of repealing it