Definition: The word 'Astro', from Greek, comes from a word meaning "sun", hence "astro" means sun. Its origin is in the ancient language of Egypt, where it was used to describe the movements of the planets that affected the Earth's climate, weather and vegetation during the solar year. Astro, when used as an adjective (meaning 'astronomical'), usually refers to a sky observation. It can also be used as an adverb meaning "in astrology". The term is often associated with the Greek word for sun ("astro"), which means sun or star. For example: "The star that you're looking at is in your astrological sign." Astrology, as its name suggests, is a branch of astrology which involves studying the movements of the stars and planets in the solar year to predict future events.