adj

• (obsolete) Convicted, attainted.
• (obsolete) Attainted; corrupted.
  "My tender youth was never yet attaint With any passion of inflaming love,"

verb

• (archaic) To subject to attainder; to condemn (someone) to death and extinction of all civil rights.
  "Tom Truth is attainted. All he has — not much — is forfeit to the king, and he is entitled to nothing but a traitorʼs death."
• (archaic) To subject to calumny; to accuse of a crime or dishonour.
  "CHARLES STUART. Attainted and proscribed by name and grade in his British regiment."
• (now rare) To taint; to corrupt, sully.
  "Amoret right fearefull was and faint, / Lest she with blame her honor should attaint […]."

noun

• (archaic) A blow or strike, especially in jousting.
  "This politic selection did not alter the fortune of the field, the challengers were still successful: one of their antagonists was overthrown, and both the others failed in the “attaint”, that is, in striking the helmet and shield of their antagonist firmly and strongly, with the lance held in a direct line, so that the weapon might break unless the champion was overthrown."
• (obsolete, law) The giving of a false verdict by a jury; the conviction of such a jury, and the reversal of the verdict.