Oct. is the short written form of October, the tenth month of the year. You meet it on calendars, forms, letters, tickets, and dates: Oct. 12, Oct. 2024. People almost never say “Oct.” out loud as a word; they say “October”. American writing sometimes drops the little dot (Oct 12); British writing more often keeps it (Oct.). It only stands for this month — not for “octagon” or “octopus”, even though the full name October comes from an old word for “eight”. The Romans counted it as month eight, before January and February sat at the front of the year, which is why the name and the number no longer match.