Luteum, also known as the corpus luteum, is a hormone-secreting structure formed in the ovaries after ovulation. It plays a crucial role in the menstrual cycle and early stages of pregnancy. Synonyms for luteum include yellow body, corpus luteal, and glandula lutea. The term yellow body refers to its yellowish appearance, while corpus luteal emphasizes its shape. Glandula lutea, meaning "yellow gland" in Latin, provides a more descriptive name for the structure. While these synonyms all refer to the same structure, they each highlight different aspects of its appearance or function.