The word "expeller" refers to a machine used to extract oils from various seeds and nuts. Some synonyms for "expeller" include screw press, oil press, oil extractor, oil expeller, and oil mill. All of these terms refer to the same type of machine that is used to mechanically extract oil from different types of seeds and nuts. These machines can be operated manually or using power, and they come in a variety of sizes and designs. Whether you need to extract oil for cooking, cosmetics, or industrial purposes, an expeller or its synonyms would be the machine you need.