Simple past tense and past participle of flop.(verb)
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Use "flopped" in a sentence
"The piece of artificial skin flopped around and he slapped it onto the damaged frame."
"Using your connections to get your kid hundreds of thousands of dollars in funding so he can buy another business after the first one he ran flopped is “providing for your family.”"
"But Wall street journal dude could be wrong, i mean, the reason it really flopped is because iron man was too damn good."