that'll be the day

idiom

—used to say that one thinks something will not happen
"Do you think he'll ever admit he made a mistake?" "That'll be the day!"

Dictionary Entries Near that'll be the day

that

that'll be the day

that'n

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“That'll be the day.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/that%27ll%20be%20the%20day. Accessed 21 Nov. 2024.

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