Simple past tense and past participle of sum.(verb)
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Use "summed" in a sentence
"In a comment made on my Frontline Club post, Al Jazeera English's Matthew Collin summed up the mood outside the courtroom."
"Russian Prime Minister Vladimir Putin summed up the significance of the Russia-China pipeline at a ceremony last month marking the completion of the 2,100-kilometer Russian section."
"They were both ejected from the game, and coach Mike Tomlin summed up how most fans felt about it succinctly: "Dumb.""