Australian
slang(?)
1. To laugh in a shrill manner
2. A humorous situation that would induce such a laugh
Short for "cackle":
1. To make the shrill
cry characteristic of a hen after laying an egg.
2. To laugh or talk in a shrill manner.
"We were,
like, at Maccas, and Sheila was drinking a
milkshake, and
like, she laughed and it came out her nose. What a cack!"