The phrase "more crack up" may seem confusing in terms of its spelling. However, by using IPA phonetic transcription, we can break it down. The first word "more" is fairly straightforward, pronounced as /mɔːr/. The second word "crack" is pronounced as /kræk/, and the final word "up" is pronounced as /ʌp/. When combined, the phrase is pronounced as /mɔːr kræk ʌp/. The phrase is often used to mean something is even funnier or more amusing than originally thought.
There is no specific term "more crack up" in the dictionary. However, given the context, it seems that you may be referring to the phrase "crack up," which is a commonly used idiomatic expression. In that case, here is a definition:
"Crack up" is an idiomatic expression that can be used as a verb to describe someone's emotional breakdown, or as a noun to refer to an outburst of laughter. When used as a verb, "to crack up" means to become mentally or emotionally overwhelmed to the point of having a breakdown, usually due to stress, pressure, or extreme emotion. It signifies an individual's loss of control over their emotions, leading to tears, hysterical laughter, or other displays of intense emotion. As a noun, "a crack up" refers to an episode or instance of uncontrollable laughter, often resulting from a joke, humorous situation, or something genuinely funny. It describes a state of uproarious amusement where one finds something immensely entertaining or hilarious.
It is important to note that "crack up" is an informal expression and is mainly used in conversational contexts rather than in formal writing. Its meaning may vary slightly depending on the context, but it generally pertains to a loss of emotional composure or an episode of extreme amusement.