Lubart m Polish (Rare, Archaic)Probably a form of
Leonard. In use since the middle ages. There is also a theory that it is a Lithuanian name, originating from Lithuanian element
ljauti meaning "to end", "to finish", "to complete", "to terminate", "to conclude", "to wind up", "to closure", "to clinch", "to cease", "to stand", "to leave off", and
barti - "to call down", "to rout", "to grapple".