one who works hard at boring tasks

a politician who belongs to a small clique that controls a political party for private rather than public ends

a mediocre and disdained writer

a tool (as a hoe or pick or mattock) used for breaking up the surface of the soil

a car driven by a person whose job is to take passengers where they want to go in exchange for money

an old or over-worked horse

a horse kept for hire

a saddle horse used for transportation rather than sport etc.