The most common and most likely answer to this crossword clue is the 2 letter word YO
I've seen this crossword clue in The Times
Y
O
More clues leading to the result YO
- Fluctuating that involves one in endless meditation?
- Ma in concert edition was very unsettled
- Show inconsistency regularly displayed by polygon
- Plaything American’s greeting twice
- Ma‘s toy-boy. O you should see him!
- Cellist gives up mother for stringed instrument?
- Ma‘s toy boy, losing head, flipped twice
- They have their ups and downs at playtime
- Toys counting for nothing in day-to-day affairs, ultimately
- Toy with graduate musician
Buddy explains!
The straight part
We know that "Fluctuating" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fluctuating = yo.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 YO mean?
YO interjection- A greeting similar to hi.
- An interjection similar to hey.
- Present! Here!
- (Baltimore) third-person singular, familiar
- Abbreviation of year/years old.
- The letter Ё, ё.
- Short for yoleven.