The most common and most likely answer to this crossword clue is the 4 letter word JEST
I've seen this crossword clue in The Times
J
E
S
T
More clues leading to the result JEST
- Joke made by judge is French
- Judge is French — that’s funny
- Plane riven by small crack
- Spades in black? I’m kidding
- Paris's first person on street to make a joke
- Son is into black example of humour
- Crack bringing head of safety into aircraft
- OK to avoid some witticisms — time for another?
- Son tossed in fountain for a joke
- Ridicule first person in French street
Buddy explains!

The straight part
We know that "example of humour" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case example of humour = jest.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 JEST mean?
JEST noun- An act performed for amusement; a joke.
- Someone or something that is ridiculed; the target of a joke.
- A deed; an action; a gest.
- A mask; a pageant; an interlude.
- To tell a joke; to talk in a playful manner; to make fun of something or someone.
- Only, simply, merely.
- (sentence adverb) Used to reduce the force of an imperative; simply.
- Used to convey a less serious or formal tone
- Used to show humility.
- (degree) absolutely, positively
- Moments ago, recently.
- By a narrow margin; closely; nearly.
- Exactly, precisely, perfectly.