The most common and most likely answer to this crossword clue is the 4 letter word VALE
I've seen this crossword clue in The Guardian
V
A
L
E
Buddy explains!
The straight part
We know that "1 down or 10 for Caesar/1 down or 10 for Caesar/low land /low land" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case 1 down or 10 for caesar/1 down or 10 for caesar/low land /low land = vale.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 VALE mean?
VALE noun- A valley.
- (usually seen in obituaries) Farewell.