Letter "U"

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Across
  1. 3. a mythical horse-like animal with one horn
  2. 4. an official who watches a game or match
  3. 5. an individual component; whole
  4. 6. not fair
Down
  1. 1. remove or break the seal of
  2. 2. made with the arm or hand below shoulder level
  3. 4. not sure