February (n.) Look up February at Dictionary.com
late 14c., ultimately from Latin februarius mensis "month of purification," from februa "purifications, expiatory rites" (plural of februum), of unknown origin, said to be a Sabine word.

The last month of the ancient (pre-450 B.C.E.) Roman calendar, so named in reference to the Roman feast of purification, held on the ides of the month. The Old English name for it was solmonað "mud month." English first borrowed the Roman name from Old French Feverier, which yielded Middle English Feverer, Feoverel, etc. (c.1200) before the 14c. respelling to conform to Latin.