The most common and most likely answer to this crossword clue is the 5 letter word THINE
I've seen this crossword clue in Financial Times
T
H
I
N
E
More clues leading to the result THINE
- Spare key, yours some time ago?
- Slim figure at last is yours!
- Article about home that was yours once
- Your old, watery eyes expressing agreement
- Fine base — yours years ago
- Your old skinny sweetheart
- It was yours long before you were born
- What you once had in the shell
- Your old skinny auntie's rear end
- Your slight error
Buddy explains!
The straight part
We know that "yours once" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case yours once = thine.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 THINE mean?
THINE pronoun- Singular second person possessive pronoun; yours