1) Disagreeable 2) Distasteful 3) Like Goneril and Regan 4) Not displaying gratitude 5) Thankless 6) Unappreciative 7) Unpleasant 8) Unthankful Found on https://www.crosswordclues.com/clue/ungrateful
• (a.) Unpleasing; unacceptable; disagreeable; as, harsh sounds are ungrateful to the ear. • (a.) Not grateful; not thankful for favors; making no returns, or making ill return for kindness, attention, etc.; ingrateful. Found on http://thinkexist.com/dictionary/meaning/ungrateful/
thanklessadjective not feeling or showing gratitude; `ungrateful heirs`; `How sharper than a serpent`s tooth it is / To have a thankless child!`- Shakespeare Found on https://www.encyclo.co.uk/local/20974
unappreciative; not displaying gratitude; not giving due return or recompense for benefits conferred: ungrateful heirs. · unpleasant; distasteful; repellent: an ungrateful task. Found on https://www.infoplease.com/dictionary/ungrateful