A machine or tool for spraying liquid, especially a big one used on farms to put water, fertiliser or pesticide over a field. A farm sprayer can be a tank on the back of a tractor with long arms reaching out sideways, or something carried on the back like a rucksack (a backpack sprayer or knapsack sprayer). The word also stretches to smaller things — a paint sprayer, a garden sprayer with a pump handle — so the size comes from the sentence, not the word. It names the equipment, not the person; a person doing the job would be 'the sprayer operator' or just 'the man spraying'. In everyday Taiwan life the small hand one is what most people picture.