The term 'BILL BLOCKER' can be broken down into four crossword solutions: VETO (4 letters), NAY (3 letters), DAN (3 letters), and OZONE (5 letters). VETO is a noun meaning the power to reject or forbid a decision or proposal of a law or government. NAY is an adverb meaning no or not in agreement. DAN is a proper noun referring to the biblical figure who was the first Israelite judge. OZONE is a noun referring to a colorless gas composed of three oxygen atoms. Finally, BETA is a noun referring to the second letter of the Greek alphabet. Together, these words describe someone who has the power to reject or forbid a decision or proposal, and is not in agreement with it.