Simple past tense and past participle of better.(verb)
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Use "bettered" in a sentence
"I think you take responsibility for the decisions that you make, and you try to make the situation bettered, which is what I have been trying to do consistently."
"This extensive report has yet to be "bettered" or superceded by anything equivalent."
"His predecessor in this career had "bettered" himself, or endeavoured to do so, by seeking the practice of some large town, and Lady Arabella, at a very critical time, was absolutely left with no other advice than that of"