The most common and most likely answer to this crossword clue is the 8 letter word LAUGHTER
I've seen this crossword clue in The Guardian
L
A
U
G
H
T
E
R
More clues leading to the result LAUGHTER
- Expression of hilarity from female offspring showing different face
- Giggling butcher chopping head off
- Sound of pleasure subsequently covering sound of disgust
- A funny reaction in gales, perhaps
- What’s fatal for many — not opening best medicine?
- Chuckles afterwards about awkward hug
- Howl perhaps that’s horrible subsequently suppressed
- Pointless massacre produces funny reaction
- Butcher’s first to go, causing tears – on the contrary!
- Start to leave after noisy cackling
Buddy explains!

The straight part
We know that "cackling" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cackling = laughter.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 LAUGHTER mean?
LAUGHTER noun- The sound of laughing, produced by air so expelled; any similar sound.
- A movement (usually involuntary) of the muscles of the laughing face, particularly of the lips, and of the whole body, with a peculiar expression of the eyes, indicating merriment, satisfaction or derision, and usually attended by a sonorous and interrupted expulsion of air from the lungs.
- A reason for merriment.