octopus [M18th] This is from Greek oktōpous, from oktō meaning eight and pous ‘foot’. The prefix gives us words like octagon [L16th] an eight-sided figure and octogenarian [E19th], someone aged between 80 and 89. In the modern world October [OE] is the tenth month, but the word comes from Latin octo because it was the eighth month in the Roman calendar. It became the tenth month after the addition of July (named after Julius Caesar), and August (named after the Emperor Augustus) in the 1st century bc.