Lord is a title with various meanings. It can denote a prince or a feudal superior

Examples of feudalism

Examples of feudalism are helpful to fully understand feudalism and feudal society. Feudalism was practiced in many different ways, depending on location and time period, thus a high-level encompassing conceptual definition does not always provide a reader with the intimate understanding that...

 (especially a feudal tenant who holds directly from the king, i.e., a baron

Baron

Baron is a title of nobility. The word baron comes from Old French baron, itself from Old High German and Latin baro meaning " man, warrior"; it merged with cognate Old English beorn meaning "nobleman"...

). The title today is mostly used in connection with the peerage of the United Kingdom

Peerage of the United Kingdom

The Peerage of the United Kingdom comprises most peerages created in the United Kingdom of Great Britain and Ireland after the Act of Union in 1801, when it replaced the Peerage of Great Britain...

 or its predecessor countries, although some users of the title do not themselves hold peerages, and use it 'by courtesy'. The title may also be used in conjunction with others to denote a superior holder of an otherwise generic title, in such combinations as "Lord Mayor

Lord Mayor

The Lord Mayor is the title of the Mayor of a major city, with special recognition.-Commonwealth of Nations:* In Australia it is a political position. Australian cities with Lord Mayors: Adelaide, Brisbane, Darwin, Hobart, Melbourne, Newcastle, Parramatta, Perth, Sydney, and Wollongong...

" or "Lord Chief Justice".