* Annual: Happening once a year.
* Anniversary: The date on which an event occurred in a previous year.
* Annually: Once a year.
* Annuity: A sum of money paid to someone each year.
* Perennial: Lasting for a year or more. (Note: This word has a different origin but shares a similar meaning).
It's worth noting that these words are often spelled with "u" instead of "u" in English, as "annus" is derived from Latin, and the spelling has evolved over time.