1. To drive together, round up
  2. To overpower; to subdue.
  3. To force, constrain or coerce.
    Logic compels the wise, while fools feel compelled by emotions.
  4. To exact, extort, (make) produce by force.
  5. To force to yield; to overpower; to subjugate.
  6. To gather or unite in a crowd or company.
  7. To call forth; to summon.

The above text is a snippet from Wiktionary: compel
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