1.  impaction(n = noun.state) - the condition of being pressed closely together and firmly fixed;
is a kind of condition, status
Derived form verb impact₁

2.  impaction(n = noun.state) - a disorder in which feces are impacted in the lower colon;
is a kind of disorder, upset

3.  impaction(n = noun.state) impacted tooth - a disorder in which a tooth is so crowded in its socket that it cannot erupt normally;
is a kind of disorder, upset

4.  impaction(n = noun.act) impingement - a sharp collision produced by striking or dashing against something;
is a kind of crash, smash

1.  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. [1913 Webster]

2.  An immovable packing; (Med.), a lodgment of something in a strait or passage of the body; as, impaction of the fetal head in the strait of the pelvis; impaction of food or feces in the intestines of man or beast. [1913 Webster]

fecal impaction