Collision involving current member, one visiting part of W London

• A sharp collision produced by striking or dashing against something
• A disorder in which a tooth is so crowded in its socket that it cannot erupt normally
• The condition of being pressed closely together and firmly fixed

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1739, from Latin impactionem (nominative impactio ) "a striking against," noun of action from past participle stem of impingere (see impinge ).

WordNet Word definitions in WordNet
n. the condition of being pressed closely together and firmly fixed a disorder in which feces are impacted in the lower colon a disorder in which a tooth is so crowded in its socket that it cannot erupt normally [syn: impacted tooth ] a sharp collision ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Impaction \Im*pac"tion\, n. [L. impactio a striking : cf. F. impaction.] (Surg.) The driving of one fragment of bone into another so that the fragments are not movable upon each other; as, impaction of the skull or of the hip. An immovable packing; (Med.), ...

Wiktionary Word definitions in Wiktionary
n. 1 compression; the packing together of loose matter 2 something packed together tightly; a mass of densely-packed matter 3 (context medicine English) a solid, immobile bulk of stool

Wikipedia Word definitions in Wikipedia
Impaction may refer to: Impaction (animals) , blockage of the digestive tract of animals Fecal impaction , the presence of a solid, immobile bulk of human feces that can develop in the rectum Dental impaction , the failure of teeth fully to erupt into the ...