Why is the ninth month called September?
1580s, "frequently met with," from Latin obvius "that is in the way, presenting itself readily, open, exposed, commonplace," from obviam (adv.) "in the way," from ob "against" (see ob-) + viam, accusative of via "way" (see via). Meaning "plain to see, evident" is first recorded 1630s. Related: Obviously; obviousness.