The most common and most likely answer to this crossword clue is the 11 letter word EXCEPTIONAL
I've seen this crossword clue in The Daily Telegraph
E
X
C
E
P
T
I
O
N
A
L
More clues leading to the result EXCEPTIONAL
Buddy explains!

The straight part
We know that "Odd" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case odd = exceptional.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 EXCEPTIONAL mean?
EXCEPTIONAL noun- An exception, or something having an exceptional value
- Forming an exception; not ordinary; uncommon; rare.
- Better than the average; superior due to exception or rarity.
- Corresponding to something of lower dimension under a birational correspondence.