A thatcher is a person whose job is to make a roof out of dried plants — straw, reeds, palm leaves, whatever grows nearby. They tie the dried stalks into thick bundles and lay them over the roof frame, layer on layer, so rain runs down the outside and never reaches the wood. A good thatched roof can last thirty or forty years, so this is a real skill, not just piling grass on a house.

It is a very old job word, and in most of the world it is now a very rare job. In England there are only a few hundred thatchers left, and they mostly repair old country cottages that the law protects. So when you meet this word in a British text, it often carries a feeling of the past, or of villages, or of expensive traditional houses. In parts of Asia and Africa, thatching is still ordinary building work rather than a heritage craft.

Because old jobs became family names in English, Thatcher is also a common surname — that is where the name of the British prime minister Margaret Thatcher comes from. Her family did not make roofs; the name just travelled down through the generations, the same way Smith, Baker and Taylor did. Students meet the surname far more often than the job, so it is worth knowing both.