Definition of "impaction" in English

noun

1. Compression; the packing together of loose matter.

2. something packed together tightly; a mass of densely-packed matter

3. (medicine) A solid, immobile bulk of stool.

4. (dentistry) Failure of a tooth to erupt into the dental arch, because of adjacent teeth, dense overlying bone, excessive soft tissue, or other factor.

5. (education) The situation where an educational institute, usually a college or university, receives more applications from qualified applicants than the number of spaces available, meaning that meeting the minimum admission requirements does not guarantee acceptance.