[ im-pak-tid ]
/ ɪmˈpæk tɪd /


tightly or immovably wedged in.
Dentistry. noting a tooth so confined in its socket as to be incapable of normal eruption.
driven together; tightly packed.
densely populated or crowded; overcrowded: an impacted school district.

Nearby words

  1. impact parameter,
  2. impact printer,
  3. impact structure,
  4. impact wrench,
  5. impact zone,
  6. impacted fetus,
  7. impacted fracture,
  8. impacter,
  9. impactful,
  10. impaction

Origin of impacted

1675–85; obsolete impact adj. (< Latin impāctus past participle of impingere to fasten, cause to collide, strike, equivalent to im- im-1 + pag-, variant stem of pangere to drive in, plant firmly + -tus past participle suffix) + -ed2; see impinge

Related formsnon·im·pact·ed, adjectiveun·im·pact·ed, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for unimpacted


/ (ɪmˈpæktɪd) /


(of a tooth) unable to erupt, esp because of being wedged against another tooth below the gum
(of a fracture) having the jagged broken ends wedged into each other
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for unimpacted


[ ĭm-păktĭd ]


Wedged together at the broken ends. Used of a fractured bone.
Placed in the alveolus in a manner prohibiting eruption into a normal position. Used of a tooth.
Packed in or wedged in such a manner so as to fill or block an organ or a passage.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.