workhorse \ˈ ̷ ̷ˌ ̷ ̷\noun 1.: a horse used chiefly for labor as distinguished from driving, riding, or racing 2. a.: a person who undertakes arduous labor b.: a markedly useful or durable vehicle, craft, or machine < helicopter today … is the workhorse of the air — W.O.Murphy > 3.: sawhorse, trestle 1a