noun which may take the genitive case particle 'no'
squished flat; flattened; crushed
Describes something that has been completely flattened or crushed out of shape, often with a sense of irreversibility. Commonly used for physical objects like boxes, cans, or hats.
箱がべちゃんこにつぶれてしまった。
The box got squished completely flat.
帽子がべちゃんこになって、もうかぶれない。
My hat got flattened and I can't wear it anymore.