what's up with that
idiom
informal
—used to ask for an explanation
"Did you hear that he quit his job?" "Yeah. What's up with that?"
Cite this Entry
“What's up with that.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/what%27s%20up%20with%20that. Accessed 31 Oct. 2025.
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Merriam-Webster unabridged
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