impacˈtion noun

1. The act of pressing together, or of fixing a substance tightly in a body cavity
2. The condition so produced

impactˈite noun

A glassy type of rock formed as a result of the impact (and heat) of a meteorite on the earth's surface

impactˈive adjective

impact'or noun

A spacecraft designed to collide into the surface of a celestial body

impact adhesive noun

A glue that forms a bond when two surfaces, each coated with the adhesive, are brought together

impacted faeces plural noun

Faeces that are so hard or dry that they cannot be evacuated through the anus

impacted fracture see under fracture

impacted tooth noun

A tooth, esp a wisdom tooth, wedged between the jawbone and another tooth and thus unable to erupt through the gum

impact parameter noun (nuclear phys)

The distance at which two particles which collide would have passed if no interaction had occurred between them

impact printer noun

Any device in which printed characters are formed on the paper by means of a hammer striking the ribbon, eg dot matrix printers, line printers