labour
Hard work, especially physical work that takes a lot of effort.
Labour is work, especially physical work or hard effort. When farmers labour in their fields, they're spending long hours planting, weeding, and harvesting crops. When construction workers labour to build a bridge, they're using their strength and skills to complete a difficult task.
It suggests serious effort, often over an extended time. A student might labour over a challenging essay, working through multiple drafts to get it right. A scientist might labour for years on a research problem.
Labour can also refer to workers as a group, especially people who do physical work. When historians talk about labour movements, they mean organized efforts by workers to improve their working conditions and wages. In the 1800s and early 1900s, labour unions fought for safer workplaces, reasonable hours, and fair pay.
In another context entirely, labour means the physical process of giving birth. When someone goes into labour, their body begins the work of bringing a baby into the world. The word captures that this is genuinely hard work, which is why we use the same term for both.