The most common and most likely answer to this crossword clue is the 6 letter word ODDITY
I've seen this crossword clue in Independent
O
D
D
I
T
Y
More clues leading to the result ODDITY
- Offbeat individual note lifted song, not a tango
- Toy did move about, a curious thing
- Misfit featured in heartless old ditty
- Curious character upset party before I’d upset heartless Tory
- Anomaly left out of ancient song
- Curiosity moving friend ultimately to DIY
- Untwinned large town abandoning its leader’s case
- Do get up to tidy around a curiosity
- It’s unusual in makeover to render home improvements but about time
- Strange thing recalled party song
Buddy explains!

The straight part
We know that "It’s unusual" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it’s unusual = oddity.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 ODDITY mean?
ODDITY noun- An odd or strange thing or opinion.
- A strange person; an oddball.
- Strangeness.