“Sub” word puzzle

123456789101112131415
Across
  1. 2. If someone “word” a group of people or country, they conquer and bring it under control by force.
  2. 4. eager and willing to do what other people want and often put your own wishes aside.
  3. 6. an adjective meaning lives or burrows underground
  4. 8. a person or thing acting or serving in place of another.
  5. 10. an evolutionary branch of a species such as dogs and wolves
  6. 13. of considerable importance, size, or worth.
  7. 14. what people talk about
  8. 15. a warship with a streamlined hull designed to operate completely submerged in the sea for long periods
Down
  1. 1. refers to a state or quality of being slightly or moderately sour or acidic.
  2. 3. coming after something in time; following. "the theory was developed “word” to the earthquake of 1906"
  3. 4. relating to or denoting a case of nouns and pronouns used for the subject of a sentence.
  4. 5. an underground platform, used to board some kind of transport
  5. 7. ideal
  6. 9. arrange to receive something, typically a publication, regularly by paying in advance.
  7. 11. making use of clever and indirect methods to achieve something.
  8. 12. to bring something under your control