The most common and most likely answer to this crossword clue is the 4 letter word NINE
I've seen this crossword clue in The Times
N
I
N
E
More clues leading to the result NINE
- Russian revolutionary backed, then beheaded in square
- Square in town in England
- Outspoken denial from Berlin cardinal
- Some men in England forming baseball team
- Figure shown by Austen in Emma
- Tyneside area containing popular square
- Crippled in heel on type of golf course
- Add this to get fourteen office hours?
- Leaders of nations in Northern Europe — a smallish number
- Elected in Tyneside square
Buddy explains!

The straight part
We know that "square" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case square = nine.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 NINE mean?
NINE noun- The digit or figure 9.
- A playing card with nine pips.
- A nine-millimeter semi-automatic pistol.
- (usually in the plural) A statistical unit of proportion (of reliability, purity, etc.).
- A baseball club, team, or lineup (composed of nine players).
- A numerical value equal to 9; the number following eight and preceding ten.
- Describing a group or set with nine elements.