Crack-up and Stack up

Crack-up noun - A mental or nervous collapse.

Stack up and crack-up are semantically related In some cases you can use "Stack up" instead a noun phrase "Crack-up".

Stack up verb - Arrange into piles or stacks.

Crack-up and stack up are semantically related in collision topic. Sometimes you can use "Crack-up" instead a noun "Stack up", if it concerns topics such as accident, unexpected.