unthank

From Middle English unthank, from Old English unþanc (“displeasure, anger, ill-will”), from Proto-Germanic *unþankaz, equivalent to un- +‎ thank. Cognate with West Frisian ontank, Dutch ondank, German Undank, Danish utak.

unthank (uncountable)

1. Lack or absence of thanks or thankfulness; thanklessness; unthankfulness; ill-will.^[1]
   • 2000, Francis G. Snyder, The Europeanisation of Law:

     It is always by this unthank that things are given to the observer that we pretend to have access to the truth of the word.

From un- +‎ thank.

unthank (third-person singular simple present unthanks, present participle unthanking, simple past and past participle unthanked)

1. (transitive) To recant; unsay, as what has been said by way of acknowledgement.
2. (transitive) To undo or retract one's thankfulness; negate, cancel, or revoke one's thanks.

unthank

1. harm; injury; misfortune
   • 1387–1400, Geoffrey Chaucer, “The Reues Tale”, in The Canterbury Tales, , →OCLC; republished in [William Thynne], editor, The Workes of Geffray Chaucer Newlye Printed, , : [Richard Grafton for] Iohn Reynes , 1542, →OCLC:

     Unthank come on his hand that bound him so.

     (please add an English translation of this quotation)