Simple past tense and past participle of wane.(verb)
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Use "waned" in a sentence
"But as his term waned, von Spakovsky became a poster boy for the blatant politicization of the federal agencies in charge of protecting voters 'rights."
"But she told us that this very moon is a new tribe come into the Dale, six long hundreds in number, and twice as many more are looked for in two eights of days, and that ere this moon hath waned, that is, in twenty-four days, they will wend their ways straight for Burgdale, for they know the ways thereto."
"Osborne said the nostalgia he felt for the days Nebraska played Oklahoma for league titles waned years ago."