| 100% | SANTA | 5 | Once-a-year flier |
| 99% | ANNUAL | 6 | Once a year |
| 99% | ANNUALLY | 8 | Once a year |
| 95% | ANNUAL | 6 | Occurring once a year |
| 95% | ANNUAL | 6 | Happening once a year |
| 93% | BUT | 3 | "Christmas comes ___ once a year" |
| 93% | ANNUAL | 6 | Book published once a year |
| 93% | ANNUAL | 6 | Occurs once a year, say |
| 92% | ANNUAL | 6 | Yearly, occurring once a year only |
| 92% | RENT | 4 | One might hike once a year |
| 92% | ANTLERS | 7 | Horns usually shed once a year |
| 92% | AGE | 3 | It goes up once a year? |
| 92% | MECCA | 5 | Its population doubles once a year |
| 90% | MECCA | 5 | City whose population triples once a year |
| 90% | ACADEMY | 7 | It's much thanked once a year |
| 90% | FRI | 3 | It's "Black" once a year: Abbr. |
| 89% | GSEVEN | 6 | International group whose leaders meet once a year |
| 89% | DECIDUOUS | 9 | Trees that shed their leaves once a year |
| 89% | SYNE | 4 | It means "since" when sung once a year |
| 87% | AGE | 3 | Number that changes for each person once a year |
| 87% | AULDLANG | 8 | With 2-Down, Burns refrain sung once a year |
| 84% | EASTEREGGS | 10 | They're rolled out once a year at the White House |
| 83% | LABOR | 5 | Something most people don't go into more than once a year |
| 75% | MTARARAT | 8 | Spot from which a dove once notably flew |
| 75% | INSIDE | 6 | "___ Weddings," wedding magazine that is published four times a year, once every season |
| 70% | JENNIFERLOPEZ | 13 | "On the Floor" singer who was once a Fly Girl on "In Living Color": 2 wds. |
| 69% | MSA | 3 | Org. that, once a year, gets together for "an exciting few days of posters and presentations, plus a fungus foray" (abbr.) |
| 68% | SANTA | 5 | "I only travel once a year. You may not see me, but you can keep what I leave behind. Who am I?" |
| 66% | ANNUAL | 6 | Once-a-year |
| 66% | DAILY | 5 | Once a day |