The "period" of time wherein a woman's period, which normally happens monthly, happens only once in a year. This is usually the result of certain Period-controlling medications that can extend the time between periods to from between 3 months to 11 months.

The Yeariod will typically be a violent cataclysm of rage and decay, lasting a week and may be thought to contribute to global warming due to the heightened Btu output in yeariodites.

the thing that you don’t have when you’re phones percentage is over 20

The yearly celebration of when a girl first started menstruating; a period anniversary.