'Thankless' definitions:

Definition of 'thankless'

(from WordNet)
adjective
Not feeling or showing gratitude; "ungrateful heirs"; "How sharper than a serpent's tooth it is / To have a thankless child!"- Shakespeare [syn: ungrateful, thankless, unthankful] [ant: grateful, thankful]
adjective
Not likely to be rewarded; "grading papers is a thankless task" [syn: thankless, unappreciated, ungratifying]

Definition of 'Thankless'

From: GCIDE
  • 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]

Words containing 'Thankless'