from
The Collaborative International Dictionary of English v.0.48
Thankless \Thank"less\, a.
1. Not acknowledging favors; not expressing thankfulness;
unthankful; ungrateful.
[1913 Webster]
That she may feel
How sharper than a serpent's tooth it is
To have a thankless child! --Shak.
[1913 Webster]
2. Not obtaining or deserving thanks; unacceptable; as, a
thankless task.
[1913 Webster]
To shepherd thankless, but by thieves that love the
night allowed. --Chapman.
[1913 Webster] -- {Thank"less*ly}, adv. --
{Thank"less*ness}, n.
[1913 Webster]