Superlative form of stingy: most stingy.(adjective)
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Use "stingiest" in a sentence
"That the greatest country on earth is also among the stingiest is a disgrace."
"DAILY DELANEY DOWNER - Having successfully passed legislation this year that will make Florida the stingiest state in America for the unemployed, Gov."
"While many of us live beyond our means, for the most part our retirement shortfall isn't due to bad savings habits but the fact that we have one of the stingiest retirement systems in the advanced world."