a person who tries to influence legislation on behalf of a special interest; a member of a lobby.
Origin of lobbyist
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a person employed by a particular interest to lobby
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
[A] strong lobbyist will permit himself to lose heavily at the poker-table, under the assumption that the great Congressman who wins the stake will look leniently upon the little appropriation he means to ask for. [George A. Townsend, "Events at the National Capital and the Campaign of 1876," Hartford, Conn., 1876]
Online Etymology Dictionary, © 2010 Douglas Harper