(law) a proceeding that permits a person to enter into a lawsuit already in progress; admission of person not an original party to the suit so that person can protect some right or interest that is allegedly affected by the proceedings; "the purpose of intervention is to prevent unnecessary duplication of lawsuits"
the act of intervening (as to mediate a dispute)
a policy of intervening in the affairs of other countries
a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance; "the tear duct was obstructed"; "the alimentary canal"; "poison is released through a channel in the snake's fangs"
a continuous tube formed by a row of elongated cells lacking intervening end walls