Simple past tense and past participle of research.(verb)
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Use "researched" in a sentence
"I seem to be in a Catch 22 situation here-friends want to buy the car but I don't think I can even sell the car legally here if all I have read and researched is accurate."
"I think IB is slightly better because its exams are usually all free response questions, with few of the multiple choice questions that make up half of AP, and because a student who goes for the IB diploma in addition to her regular high school diploma must write a 4,000 word researched essay."
"SCHWARTZBEIN: My complaint with that chapter is it has not been thoroughly researched, which is what everybody is saying."