English to English

verb (v)

• become or cause to become unobstructed(verb.contact)

  Example:
  The chemical that we poured down the drain unclogged it.
  

  Antonym:
  back up, choke, choke off, clog, clog up, congest, foul
  

  source: wordnet30
• To disencumber of a clog, or of difficulties and obstructions; to free from encumbrances; to set at liberty.(verb)

  source: webster1913