Simple past tense and past participle of overmaster.(verb)
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Use "overmastered" in a sentence
"The obstinacy of age had, in short, overmastered its complaisance, and the young woman said no more."
"The defense has not disputed whether he was the gunman, focusing instead on his mental state and claiming he suffers from a disorder that "overmastered" his will to refrain from criminal acts."
"Already we have had the syntax overmastered by feeling, affection leaping and soaring over ground through which reason would have traversed most tediously slow."