workhorse

n. horse used for labor; person who works very hard; very useful or dependable machine or vehicle

Workhorse is: An expression that refers to the draft horse common in agricultural societies. The expression can refer to a machine, one that performs dependably under heavy, prolonged use, or a person, who works tirelessly at difficult, time-consuming tasks.Workhorse brand chassis for motor homes and step vans owned by Navistar International. See Workhorse Custom Chassis.
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Noun
1. machine that performs dependably under heavy use; "the IBM main frame computers have been the workhorse of the business world"
(hypernym) machine
2. a horse used for plowing and hauling and other heavy labor
(hypernym) horse, Equus caballus
(hyponym) plow horse, plough horse

Synonyms and related words:
beast of burden, bidet, buck, carriage horse, cart horse, cavalry horse, draft horse, dray horse, driving horse, drudge, fag, fill horse, filler, galley slave, gigster, greasy grind, grind, grub, hack, hackney, horse, hunter, jument, lead, leader, mount, pack horse, palfrey, peon, plodder, plow horse, pole horse, polo pony, post-horse, remount, rider, riding horse, road horse, roadster, rouncy, saddle horse, saddler, sawbuck, shaft horse, slave, slavey, slogger, stalking-horse, sumpter, sumpter horse, swot, thill horse, thiller, toiler, trestle, wheeler, wheelhorse
  

CAVALLO DA LAVORO. GRAN LAVORATORE. MULO