Simple past tense and past participle of flip-flop.(verb)
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Use "flip-flopped" in a sentence
"Cooper’s expression flip-flopped from paralyzed fear to outright joy."
"Lieberman has flip-flopped like a mackerel for years so who knows what he'll do."
"Senators who had sided with Mr. Durbin last year were reluctant to switch sides, both because they didn't want voters back home to think they had flip-flopped or backed Wall Street, lawmakers and lobbyists said."