The crossword solution for the term COMPOS is MENTIS, which is a Latin word meaning 'MIND' or 'INTELLECT'. It is often used in philosophy to refer to the mental faculties of an individual, such as their ability to reason and think. It is also used in psychology to refer to the mental processes involved in understanding and making decisions. In music, it is used to refer to the act of composing or creating a piece of music.