Black's Law Dictionary (2nd edition)dictionaries

Dominus Litis

Lat. Tbe master of the suit; i. e., the person who was really and directly lnterested in the suit as a party, as dlstlngulshed from hls attorney or advocate. Bnt the term is also applied to one who, though not orlglnally a party, has made hlm-self such, hy lnterventlon or otherwlse, and has assumed entlre control* and responsihll-ity for one side, and is treated by the court as liable for costs. See In re Stover, 1 Curt. 201, Fed. Cas. No. 13,507

Source: Black’s Law Dictionary 2nd Ed (1910)