What do October, octopus and octagon have in common? They all begin with “octo(a)” meaning “8” in Latin and Greek.
While an octagon is an eight-sided shape, and an octopus has eight arms, October is the tenth month. Why is it not the eighth month? To find the 
answer we must journey back to the ancient Roman Empire. At that time, the Roman calendar had 10 months. The months were Martius (March), Aprilis (April), Maius (May), Lunius (June), Quintilis (5th month), Sextilis (6th month), September (7th month), October (8th month), November (9th month) and December (10th month). While the first four months were named for Roman gods, the last six simply had the number in the name. With more understanding of the solar year, the calendar was adjusted with two months, Ianuarius (January) and Februarius (February), being added to the beginning of the year resulting in October becoming the tenth month.
Additionally, Quintilis, now the 7th month, was renamed Julius (July) in honor of Julius Caesar and Sextilis, now the 8th month, was renamed Augustus (August) in honor of Emperor Augustus).
A note to help increase your understating of English, when you see the prefixes “quint” or “penta’ meaning 5, “sext” or “hexa” meaning 6, “sept” or “hepta” meaning 7, “octo” meaning 8, “nona” meaning 9, or “deca” or (deci) meaning 10 at the beginning of a word, it could be telling you that word is associated with that number. Woman gives birth to septuplets in a first known case in Iraq.
Erik