The Collaborative International Dictionary
Unthank \Un*thank"\, n. [AS. unpank. See Un- not, Thank.] No thanks; ill will; misfortune. [Obs.]
Unthank come on his head that bound him so.
--Chaucer.
Wiktionary
Etymology 1 n. 1 Lack or absence of thanks or thankfulness; thanklessness; unthankfulness; ill-will. 2 harm; injury; misfortune. Etymology 2
vb. 1 (lb en transitive) To recant; unsay, as what has been said by way of acknowledgement. 2 (lb en transitive) To undo or withcall one's thankfulness; negate, cancel, or revoke one's thanks.
Wikipedia
Unthank can refer to:
Usage examples of "unthank".
Not he to feed upon a breast unthanked, Or eye a beauteous face in a cracked glass.
Overlooked, unthanked, I turned sulky, and when this mood, one I can never maintain for long, wore off, I threw myself into the dissipation about me with angry zeal.
And in another house nearby, he boarded Richardson and McKenzie, 800m runner Paul Byrne, and Steepler Chris Unthank.