Eighteen

6. the opening in a photographic lens that admits the light passing through
8. lacking or exhibiting a lack of moral principles
10. performed a full turn on the toe or ball of one foot in ballet
11. a person of great authority or wisdom whose opinions or judgments are regarded with great respect
12. a sheep of an English breed of large long-wooled sheep
13. a blue-veined cheese with wrinkled rind made of whole cows' milk

1. figure in Greek mythology who flies away from imprisonment using artificial wings but falls when he flies too close to the sun
2. one of the portions into which something is divided : component, part
3. having the appearance of mother-of-pearl
4. animals belonging to a large class of invertebrates comprising the majority of the marine or freshwater arthropods
5. an evergreen tree or shrub mostly native to western Australia
7. no longer used or popular due to being very old : obsolete
9. enormous, immense