The most common and most likely answer to this crossword clue is the 7 letter word PLAYFUL
I've seen this crossword clue in The Daily Telegraph
P
L
A
Y
F
U
L
More clues leading to the result PLAYFUL
- Jesting, pull a fairy’s wings off
- Jolly priest was prostrate with flu, shivering
- In high spirits, having got full pay organised
- Philip lay fulminating about teasing
- The Entertainer, for example, almost perfectly jolly
- Frivolous production’s almost sold out
- Piano melody, getting loud, starts to unwind later in high-spirited style
- “Returns Only” … “Must End Shortly”
Buddy explains!

The straight part
We know that "jolly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case jolly = playful.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 PLAYFUL mean?
PLAYFUL adjective- Liking play, prone to play frequently, such as a child or kitten; rather sportive.
- Funny, humorous, jesting, frolicsome.
- Fun, recreational, not serious.
- Experimental.