| Answer | Crossword Clue |
|---|---|
| os | the fifteenth letter of the English alphabet |
| oes | the fifteenth letter of the English alphabet |
| as | the first letter of the English alphabet |
| es | the fifth letter of the English alphabet |
| is | the ninth letter of the English alphabet |
| us | the twenty-first letter of the English alphabet |
| digamma | letter of the early Greek alphabet that generally fell into disuse in Attic Greek before the classical period and that represented a sound similar to English w |
