.............

Unthank:
From a noun “unthank” that had been out of use for a century by Pepys’ day, but of course obsolete words often live on as surnames. OED:
[OE. unþanc masc. (f. un- UN-1 12 + þanc THANK n.), = OFris. unthonk (WFris. ontank, NFris. untoonk), MDu. ondanc (Du. ondank), MLG. undank, OHG. undanch, unthank (MHG. undanc, G. undank) ingratitude, displeasure, etc.; ON. úþökk fem., a reproach, censure, etc. (MSw. othak, Sw. otack, MDa. and Da. utak ingratitude, etc.).]
I. 1. Absence of gratitude or good-will; unfavourable thought or feeling; ill-will, disfavour; displeasure expressed in actions or words.
[etc.]

Note that the “THANK n.” mentioned in the etymology is not the word we’re used to but an obsolete noun meaning ‘thought.’

User Posted Link

Posted By: Tricky Hawes, Aug 6, 10:15:51