| 100% | OED | 3 | Its first complete ed. was published in 1928 |
| 46% | OED | 3 | Its first vol., A-Ant, was published in 1884 |
| 46% | RAMADA | 6 | Its first hotel was in Flagstaff |
| 46% | IKEA | 4 | Its first store was in Älmhult |
| 45% | IKEA | 4 | Its first store was in Älmhult, Smaland |
| 45% | AIRMAIL | 7 | Its first stamps were issued in 1918 |
| 44% | SNL | 3 | Its first host, in 1975, was George Carlin: Abbr. |
| 44% | WHITEHOUSE | 10 | Its first radio was installed by Harding in 1922 |
| 43% | HYDROGENBOMB | 12 | It was first tested in 1952 |
| 43% | MTMCKINLEY | 10 | It was first climbed in 1913 |
| 43% | 4MINUTEMILE | 11 | It was first broken in 1954 |
| 43% | EVEREST | 7 | It was first conquered in 1953 |
| 43% | NEPTUNE | 7 | It was first observed in 1846 |
| 43% | MATTERHORN | 10 | It was first conquered in 1865 |
| 42% | DNA | 3 | It was first correctly modeled in ''Nature'' (1953) |
| 42% | ATOM | 4 | It was first split at Cambridge in 1932 |
| 41% | EROICA | 6 | It was first publicly performed in Vienna in 1805 |
| 41% | BOYSENBERRY | 11 | It was first cultivated in California by Walter Knott |
| 41% | ELDORADO | 8 | The first complete navigation of the Amazon was in search of this |
| 41% | NEVADA | 6 | Locally, its first "a" is pronounced as in "trap" |
| 40% | FATHERSDAY | 10 | It was first officially designated in a 1966 Lyndon Johnson proclamation |
| 40% | STEREO | 6 | "Fantasia" was the first commercial film shown in it |
| 39% | RADIO | 5 | It was used to play music for the first time in 1906 |
| 39% | HOFF | 4 | Harry S —, English author whose 1934 debut novel Trina was published in the US as It Happened in PRK |
| 39% | TRIPLELUTZ | 10 | Donald Jackson was first to land it in international competition |
| 39% | HOPI | 4 | Language whose first dictionary was published in 1998 |
| 39% | TECATE | 6 | Mexican beer named for the city it was first produced in |
| 38% | MILE | 4 | Roger Bannister was the first to run it in under four minutes |
| 38% | PGA | 3 | Babe Zaharias was the first woman to compete on its tour, in brief |
| 37% | MLBDRAFT | 8 | A-Rod was its first pick in 1993 |