The Collaborative International Dictionary
Thankless \Thank"less\, a.
-
Not acknowledging favors; not expressing thankfulness; unthankful; ungrateful.
That she may feel How sharper than a serpent's tooth it is To have a thankless child!
--Shak. -
Not obtaining or deserving thanks; unacceptable; as, a thankless task.
To shepherd thankless, but by thieves that love the night allowed.
--Chapman. [1913 Webster] -- Thank"less*ly, adv. -- Thank"less*ness, n.
Wiktionary
adv. In a thankless manner, ungratefully.
Usage examples of "thanklessly".
As a joke I almost bring Tim a Bellini but he seems far too edgy tonight to appreciate this so I wade back through the crowd to where he stands and hand him the Absolut and he takes it thanklessly and finishes it with one gulp, looks at the glass and grimaces, giving me an accusatory look.