Green’s Dictionary of Slang

(US) a vice-president; also attrib.

1949		Wash. Post 28 May B14: (ProQuest) [Bob] Hope has become a favorite pal of Veep Alben Barkley.
1955		S.V. Baum ‘From “Awol” to “Veep”’ in AS XXX:2 108: Veep came in, first applied to former Vice-President of the United States Alben W. Barkley but later used in generalized sense for the vice-president of any organization.
1972		T. Lippman Spiro Agnew’s America 175: The Veep Routine Duties The Constitution of the United States assigns the vice-president two responsibilities [etc.].
1974		T. Crouse Boys on the Bus 295: Of course, there were a few brief flashes of the old Agnew, such as when the Veep opined that someone had ‘set up’ the Watergate break-in.
1994		G.F. Will Leveling Wind 285: The Veep and the Blatherskite The more thoughtful half of the Bush-Quayle team has recently been brimming over with thoughts.
2002		J. Lerner You Got Nothing Coming 337: ‘Hey, Jimmy — did you hear about Don Lee, the quality veep?’ ‘Not yet, Paul. Why?’ ‘He’s fucking history!’.
2009		(con. 1960s) J. Ellroy Blood’s a Rover 18: Wayne Senior [...] sucked up to former veep Dick Nixon.