An unerupted or partially erupted tooth so positioned that complete eruption is unlikely.
A tooth which is held against another tooth and so cannot grow normally.
A tooth blocked from appearing in the mouth because the jaw is already overcrowded with teeth. An impacted tooth can become infected and painful, requiring extraction; it can also damage other teeth or cause the opposite tooth to grow abnormally long.
Tooth, usually a wisdom tooth, so firmly wedged in the socket that it cannot break through the gum.