thankless

• POS: Adjective
• HYPHEN: thank=less

CIDE DICTIONARY

thankless, a. 

•  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!"  [1913 Webster]
•  Not obtaining or deserving thanks; unacceptable; as, a thankless task.  [1913 Webster]

  "To shepherd thankless, but by thieves that love the night allowed."  [1913 Webster]

OXFORD DICTIONARY

thankless, adj.
1 not expressing or feeling gratitude.
2 (of a task etc.) giving no pleasure or profit.
3 not deserving thanks.

Derivative

thanklessly adv. thanklessness n.

THESAURUS

thankless

bitter, bootless, careless, despised, disagreeable, dislikable, disliked, displeasing, distasteful, fruitless, futile, heedless, lowly, miserable, misprized, misunderstood, out of favor, profitless, self-centered, sour, thoughtless, ugly, unacknowledged, unalluring, unappealing, unappetizing, unappreciated, unappreciative, unattractive, uncared-for, undelectable, undelicious, undesirable, unengaging, unenjoyable, ungrateful, uninviting, unlamented, unlikable, unmindful, unmissed, unmourned, unpalatable, unpleasant, unpleasing, unpopular, unprofitable, unregretted, unrequited, unrewarding, unsavory, unsung, untasteful, unthankful, unvalued, unwelcome, useless, vain, wretched

ROGET THESAURUS

thankless

Painfulness

N painfulness, trouble, care, trial, affliction, infliction, blow, stroke, burden, load, curse, bitter pill, bitter draught, waters of bitterness, annoyance, grievance, nuisance, vexation, mortification, sickener, bore, bother, pother, hot water, sea of troubles, hornet's nest, plague, pest, cancer, ulcer, sting, thorn, canker, scorpion, dagger, scourge, carking care, canker worm of care, mishap, misfortune, desagrement, esclandre, rub, source of irritation, source of annoyance, wound, open sore, sore subject, skeleton in the closet, thorn in the flesh, thorn in one's side, where the shoe pinches, gall and wormwood, sorry sight, heavy news, provocation, affront, head and front of one's offending, infestation, molestation, malignity, causing pain, hurting, hurtful, painful, dolorific, dolorous, unpleasant, unpleasing, displeasing, disagreeable, unpalatable, bitter, distasteful, uninviting, unwelcome, undesirable, undesired, obnoxious, unacceptable, unpopular, thankless, unsatisfactory, untoward, unlucky, uncomfortable, distressing, afflicting, afflictive, joyless, cheerless, comfortless, dismal, disheartening, depressing, depressive, dreary, melancholy, grievous, piteous, woeful, rueful, mournful, deplorable, pitiable, lamentable, sad, affecting, touching, pathetic, irritating, provoking, stinging, annoying, aggravating, mortifying, galling, unaccommodating, invidious, vexatious, troublesome, tiresome, irksome, wearisome, plaguing, plaguy, awkward, importunate, teasing, pestering, bothering, harassing, worrying, tormenting, carking, intolerable, insufferable, insupportable, unbearable, unendurable, past bearing, not to be borne, not to be endured, more than flesh and blood can bear, enough to drive one mad, enough to provoke a saint, enough to make a parson swear, enough to gag a maggot, shocking, terrific, grim, appalling, crushing, dreadful, fearful, frightful, thrilling, tremendous, dire, heart-breaking, heart-rending, heart-wounding, heart-corroding, heart-sickening, harrowing, rending, odious, hateful, execrable, repulsive, repellent, abhorrent, horrid, horrible, horrific, horrifying, offensive, nauseous, nauseating, disgusting, sickening, revolting, nasty, loathsome, loathful, fulsome, vile, hideous, sharp, acute, sore, severe, grave, hard, harsh, cruel, biting, caustic, cutting, corroding, consuming, racking, excruciating, searching, grinding, grating, agonizing, envenomed, catheretic, pyrotic, ruinous, disastrous, calamitous, tragical, desolating, withering, burdensome, onerous, oppressive, cumbrous, cumbersome, painfully, with pain, deuced, Int, hinc illae lachrymae!, surgit amari aliquid, the place being too hot to hold one, the iron entering into the soul, he jests at scars that never felt a wound, I must be cruel only to be kind, what deep wounds ever closed without a scar?.

Ingratitude

N ingratitude, thanklessness, oblivion of benefits, unthankfulness, benefits forgot, thankless task, thankless office, ungrateful, unmindful, unthankful, thankless, ingrate, wanting in gratitude, insensible of benefits, forgotten, unacknowledged, unthanked, unrequited, unrewarded, ill- requited, Int, thank you for nothing!, thanks for nothing!, et tu Brute!, ingratitude! thou marble-hearted fiend.