lis

Lis, litis, f., third declension. The nominative hides the stem: everything after it is built on lit-, so litem, lite, lites, litium, and it declines as an i-stem. The older spelling was stlis, which explains why the nominative looks so unlike the rest.

Legal Latin gives it the phrases worth knowing. "Litem contestare" was the formal joining of issue that fixed what a Roman trial was actually about, and "lis pendens", a suit still hanging, is still current in English and Scots law. Outside court it thins out to any quarrel, and Horace can use it of a squabble between neighbours. English took litigation and litigious from the same root and, unusually, kept the tone: nobody calls a person litigious as a compliment.