| 100% | DAY | 3 | Green ___ ("21st Century Breakdown" band) |
| 55% | ENEMY | 5 | "Know Your ___" (Green Day single from "21st Century Breakdown") |
| 50% | DORA | 4 | 21st century explorer |
| 48% | LASERMOUSE | 10 | 21st century gaming accessory |
| 46% | IMS | 3 | Contacts 21st century-style |
| 45% | UPDATE | 6 | Bring into the 21st century |
| 45% | MMI | 3 | Start of the 21st century |
| 44% | DOTCOMEXPLOSION | 15 | Boom of the early 21st century |
| 44% | OBAMACRAT | 9 | Certain liberal of the 21st century |
| 44% | DAY | 3 | Green ___ ("American Idiot" band) |
| 44% | DAY | 3 | Green ___, American rock band |
| 42% | CIRQUE | 6 | __ du soleil, traveling show for the 21st century |
| 40% | NOAH | 4 | "21 Lessons for the 21st Century" author Yuval ___ Harari |
| 39% | DATASCIENTIST | 13 | "Sexiest job of the 21st century," per Harvard Business Review |
| 39% | BROKEBACKMOUNTAIN | 17 | Couple in the 21st century with Best Director Oscar winners |
| 38% | LORDE | 5 | "The 21st century's author of adolescent evolution," per Cyrena Touros |
| 38% | NEW | 3 | 21st-century |
| 37% | SAMUELALITO | 11 | Second Supreme Court justice confirmed in the 21st century (2006): 2 wds. |
| 37% | SONIASOTOMAYOR | 14 | Third Supreme Court justice confirmed in the 21st century (2009): 2 wds. |
| 37% | JOHNROBERTS | 11 | First Supreme Court justice confirmed in the 21st century (2005): 2 wds. |
| 37% | RAVENSYMONE | 11 | Actress in "The Cheetah Girls" and "Zenon: Girl of the 21st Century" |
| 37% | MML | 3 | 21st-century year |
| 37% | EURO | 4 | 21st-century currency |
| 36% | ADELE | 5 | Artist behind the best-selling album of the 21st century (30+ million units) |
| 36% | THESWINEFLU | 11 | 21st-century epidemic concern |
| 36% | LAURA | 5 | 21st-century first lady |
| 36% | OPIOIDS | 7 | 21st-century health menace |
| 36% | AMISH | 5 | 21st-century buggy drivers |
| 36% | OBAMAS | 6 | 21st-century first family |
| 35% | BIDEN | 5 | 21st-century vice president Joe |