A decade is a period of ten years. The word is derived (via French and Latin) from the Ancient Greek: δεκάς (/ ðɛkˈɑːs /, transliteration = dekas), which means a group of ten. Other words for spans of years also come from Latin: biennium (2 years), triennium (3 years), quadrennium (4 years), lustrum (5 years), century (100 years), millennium (1000 years).
1 decade is equal to how many years
ten years