The master of the servants of a household; the master of a feudal manor

One possessing similar mastery over others; any feudal superior generally; any nobleman or aristocrat; any chief, prince, or sovereign ruler; in Scotland, a male member of the lowest rank of nobility (the equivalent rank in England is baron)

One possessing similar mastery in figurative senses (esp. as lord of ~)

Domineer or act like a lord.

To invest with the dignity, power, and privileges of a lord; to grant the title of lord.