bullock
A young male cow used for pulling carts and plows.
A bullock is a young male cow that has been castrated, which means it can't reproduce. Farmers have raised bullocks for thousands of years because they're strong, steady workers perfect for pulling plows, wagons, and carts.
Before tractors and trucks existed, bullocks were essential to farming and transportation. A team of bullocks could pull a heavy plow through hard soil all day without tiring as quickly as horses. In many parts of the world, farmers still use bullocks for fieldwork because they're reliable, don't need expensive fuel, and can work in terrain where modern machinery struggles.
You'll often see the word in historical novels about farming life or in stories set in countries like India, where bullock carts remain common. A bullock is generally calmer and easier to work with than a full bull, which is why farmers preferred them for steady, patient labor rather than for breeding.
You might also hear the similar word steer, which means nearly the same thing in American English, though bullock is more common in British English and other parts of the world.