The most common and most likely answer to this crossword clue is the 6 letter word ELEVEN
I've seen this crossword clue in The Times
E
L
E
V
E
N
More clues leading to the result ELEVEN
- Flat behind the Spanish cardinal
- Team assembled by the Spanish, no less
- It's not odd to follow the Spanish cardinal
- Spaniard, no longer with Man U, quits team
- Interior of bell on flat side
- How many fitted in back of taxi?
- One third of twelve - not odd number
- One third of twelve still an odd number
- Football or cricket team’s prime?
- Cricket team in novel event
Buddy explains!

The straight part
We know that "odd number" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case odd number = eleven.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 ELEVEN mean?
ELEVEN noun- A cricket team of eleven players. Hence first eleven - the team of best cricket players (at a school), second eleven - the "B" team, etc.
- A football team of eleven players; the starting lineup.
- Used instead of ! to amplify an exclamation, imitating someone who forgets to press the shift key while typing exclamation points.
- A number off the charts of a hypothetical scale of one to ten.
- The cardinal number occurring after ten and before twelve. Represented as 11 in Arabic digits.