lobbyist
definition
a person who seeks to influence political decisions on behalf of a particular interest group
example
The lobbyist argued passionately for environmental reforms that would benefit her organization and the planet.
synonyms
advocateinfluencercampaigner
word origin — The term 'lobbyist' originates from the word 'lobby', which refers to a corridor or waiting area in a legislative building where people could meet with lawmakers. The usage dates back to the mid-19th century.