The most common and most likely answer to this crossword clue is the 4 letter word LORD
I've seen this crossword clue in The Times
L
O
R
D
More clues leading to the result LORD
- Expressed praise for God
- Either limit to land for nobleman
- Knowledge finally lost by deceased ruler
- In recital, praise God
- Drunkard supposedly partial to mezcal or daiquiri
- Owner of ground and one end of land?
- Which of land’s borders is for ruler?
- Supposed drunkard, not entirely witty, knocked over
- Superior rum knocked back, disposing of one litre
- Some earl or duke? Possibly
Buddy explains!

The straight part
We know that "nobleman" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nobleman = lord.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does LORD mean?
LORD noun- 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 ~)
- The heavenly body considered to possess a dominant influence over an event, time, etc.
- A hunchback.
- (via Cockney rhyming slang) Sixpence.
- Domineer or act like a lord.
- To invest with the dignity, power, and privileges of a lord; to grant the title of lord.