The term 'HIGHEST STAGES' can be solved by the five-letter word 'ACMES'. This word is derived from the Greek word akme, which means 'the highest point or stage of development'. It is often used to refer to the peak of a process or activity, such as the highest stage of a mountain or the highest stage of a career. In other contexts, it can also refer to the most advanced or successful level of something, such as the highest stage of technology or the highest stage of education.