Is ‘thankless’ a Scrabble US Word? Yes
Is ‘thankless’ a Scrabble UK Word? Yes
Is ‘thankless’ a Words With Friends Word? Yes
Is ‘thankless’ an Adjective? Yes
Is ‘thankless’ an Adverb? No
Is ‘thankless’ a Noun? No
Is ‘thankless’ a Verb? No
- Shakespeare;
"How sharper than a serpent's tooth it is / To have a thankless child!"
not likely to be rewarded;

See also: Words That Rhyme With THANKLESS →