Someone who advises a public figure or maintains a professional role that does not garner public attention. Originally used to describe scientists and technicians who worked without public knowledge or recognition in the United Kingdom during World War II. Primarily heard in UK. Although he is a skilled political strategist, he lacks the charm and charisma necessary to run for office himself and, therefore, is likely to stay a backroom boy for the rest of his career.

A group of men engaged in clandestine decision-making. We're not fools—we know that the boys in the back room actually have all the power around here.