Simple past tense and past participle of embitter.(verb)
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Use "embittered" in a sentence
"How long this state of things is to continue -- how long this temper of murderous treason is to remain, suppressed, indeed, but not dead -- how long it is to exist, scattered and concealed, but alive and rankling in embittered and desperate bosoms, or perhaps fostered and deliberative in the darkness of secret organizations-this is the first and foremost of the"
"They are possibly a trifle embittered, which is an excellent demeanour for mankind in the face of inscrutable heaven."
"I can attest that curbing your own ambitions to satisfy the embittered is a losing proposition."