intervention

英 [ɪntə'venʃ(ə)n] 美[,ɪntɚ'vɛnʃən]

• n. 介入；调停；妨碍

1. the act of intervening (as to mediate a dispute)

2. a policy of intervening in the affairs of other countries

3. (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"