The most common and most likely answer to this crossword clue is the 7 letter word TEE-HEE
I've seen this crossword clue in The Guardian
T
E
E
-
H
E
E
More clues leading to the result TEE-HEE
Buddy explains!
The straight part
We know that "Laugh" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case laugh = tee-hee.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 TEE-HEE mean?
TEE-HEE interjection- A typographical representation of tittering or high-pitched laughter.