Simple past tense and past participle of downshift.(verb)
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Use "downshifted" in a sentence
"And as the music downshifted to its slowest, most glacial thump, fans would throw their hands over their heads, as if tossing a soccer ball into play."
"He nearly wrecked the bike and downshifted to third gear before glancing up again."
"Regin downshifted, tires squealing as she swerved to dodge a roadkill-bound possum."