The word(s) "thankless" appears 9 time(s) in 8 verse(s) in Quran in Muhammad Pickthal translation.

(1) And if we cause man to taste some mercy from Us and afterward withdraw it from him, lo! he is despairing, thankless.

(2) And when your Lord proclaimed: If ye give thanks, I will give you more; but if ye are thankless, lo! My punishment is dire.

(3) And Moses said: Though ye and all who are in the earth prove thankless, lo! Allah verily is Absolute, Owner of Praise.

(4) Hast thou not seen those who gave the grace of Allah in exchange for thanklessness and led their people down to the Abode of Loss,

(5) And when harm toucheth you upon the sea, all unto whom ye cry (for succour) fail save Him (alone), but when He bringeth you safe to land, ye turn away, for man was ever thankless.

(6) Or feel ye secure that He will not return you to that (plight) a second time, and send against you a hurricane of wind and drown you for your thanklessness, and then ye will not find therein that ye have any avenger against Us?

(7) And how many a community have We destroyed that was thankless for its means of livelihood! And yonder are their dwellings, which have not been inhabited after them save a little. And We, even We, were the inheritors.

(8) If ye are thankless, yet Allah is Independent of you, though He is not pleased with thanklessness for His bondmen; and if ye are thankful He is pleased therewith for you. No laden soul will bear another's load. Then unto your Lord is your return; and He will tell you what ye used to do. Lo! He knoweth what is in the breasts (of men).