Mono-

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Across
  1. 2. a track for subway or train cars that only has one rail
  2. 4. control of a product or service by one company
  3. 5. having only one syllable
  4. 7. having one color; a painting, design, photo, or outfit that is only one color or shades of one color
  5. 8. an eyeglass for one eye
Down
  1. 1. something made out of one single large block or piece of stone; one single stone monument
  2. 2. speaking or writing only one language
  3. 3. an abnormal feeling of being the only one there; fear of being alone
  4. 5. a long speech given by one person
  5. 6. a speech in which every word has one tone of voice