impaction (n.)

  1. the condition of being pressed closely together and firmly fixed

  2. a disorder in which feces are impacted in the lower colon

  3. a disorder in which a tooth is so crowded in its socket that it cannot erupt normally

    [ Syn: impacted tooth ]

  4. a sharp collision produced by striking or dashing against something

    [ Syn: impingement ]

The dictionary is based on the WordNet Electronic Lexical Database.
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