| 100% | EON | 3 | The Hadean was the Earth's first, ending about 4 billion years back |
| 76% | EON | 3 | The Hadean was the first one, ending about 4 billion years ago |
| 51% | EON | 3 | The Hadean was the earth's first one |
| 38% | EST | 3 | 4.5 billion years, for the age of the earth: Abbr. |
| 36% | SIMPLYRED | 9 | “Holding Back the Years” band, whose first incarnation was the Frantic Elevators |
| 36% | RADIUS | 6 | Earth's is about 4,000 miles |
| 35% | REDGIANT | 8 | The sun, e.g., in about five billion years |
| 34% | ASIA | 4 | Continent that is about 30% of the earth's land |
| 34% | NEONPILL | 8 | Cage the Elephant studio album that was the band’s first in five years (May, 2024) |
| 33% | JEEP | 4 | The 2020 Gladiator is this brand's first pick-up truck in over 25 years |
| 33% | SUN | 3 | Solar System's star that is over 4.5 billion years old |
| 32% | WALLIS | 6 | Simpson who was Time's first Woman of the Year |
| 32% | TWEET | 5 | The first was in July 2006, but it was the American Dialect Society's word of the year in 2009 |
| 32% | BESTOFMYLOVE | 12 | Song by the Emotions that was #3 on Billboard's year-end Hot 100 for 1977: 4 wds. |
| 32% | KIPOANDTHEAGE | 13 | With 32-Across, animated series about a girl from beneath the Earth's surface: 4 wds. |
| 32% | PAGE | 4 | "Tomorrow is the first ___ in a book of 365" (common New Year's phrase) |
| 31% | ALI | 3 | The 2001 sports film which is about ten critical years in the life of America's greatest boxer |
| 31% | AVATAR | 6 | 2009 movie that was the first film to gross over $2 billion |
| 31% | ITSGROWINGONME | 14 | "I wasn't sure at first, but ...," or what could be said about the ends of 16-, 26-, and 44-Across? |
| 31% | EVAPERON | 8 | Evita the musical was about this first lady |
| 30% | FORTYFIVE | 9 | The year WWII ended was nineteen __ |
| 30% | FIGHTCLUB | 9 | The first rule is that you do not talk about it |
| 30% | EER | 3 | "This is the first truth that ___ thine own tongue was guilty of": "All's Well That Ends Well" |
| 30% | MCMII | 5 | Year the first Rose Bowl was played |
| 30% | PROFESSOR | 9 | "The ___," Charlotte Bronte's first novel about a teacher, which was published posthumously |
| 30% | GLENN | 5 | John who was the first American to orbit the earth |
| 30% | LAIKA | 5 | Dog that was the first animal to orbit the Earth |
| 30% | LIFE | 4 | Its first documented appearance was 3.5 billion years ago |
| 30% | MCMIII | 6 | Year the first Tour de France was held |
| 29% | INNERCORE | 9 | The earth's is largely iron |