lit·i·gate 
(lĭtĭ-gāt′)
(lĭtĭ-gāt′)v. lit·i·gat·ed, lit·i·gat·ing, lit·i·gates
v.tr.
To prosecute or defend (a lawsuit or legal action); pursue (a legal case).
v.intr.
To bring a lawsuit or defend against a lawsuit in court.
[Latin lītigāre, lītigāt- : līs, līt-, lawsuit + agere, to drive; see ag- in the Appendix of Indo-European roots.]
liti·ga·ble (-gə-bəl) adj.
lit′i·gation n.
liti·ga′tor n.