The most common and most likely answer to this crossword clue is the 3 letter word OOH
I've seen this crossword clue in Financial Times
O
O
H
More clues leading to the result OOH
- Excited exclamation Dorothy regularly let out
- Bear scratching head well!
- Husband loves taking lead? How exciting!
- How nice hotel supports pair
- Bear with shaved head? Well I never!
- Rings husband. That’s nice!
- Wow, Ringo’s hot!
- 5 Pleased cry from Winnie throwing hat away?
- Bear with head cut off? I say!
- Golly! Storybook bear needs no introduction
Buddy explains!

The straight part
We know that "How exciting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case how exciting = ooh.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 OOH mean?
OOH noun- An exclamation of ooh.
- To exclaim ooh.
- An expression of surprise.
- An expression of awe.
- A sound made to imitate a ghost.
- An expression of affection.
- An expression of pain.