| Answer | Crossword Clue |
|---|---|
| HOUR | Compline or sext |
| ETTES | Suffix with sept or sext. |
| astrolabe | astronomical instrument for taking the altitude of the sun or stars and for the solution of other problems in astronomy and navigation: used by Greek astronomers from about 200 b.c. and by Arab astronomers from the Middle Ages until superseded by the sext |
