The word(s) "grievous" appears 89 time(s) in 89 verse(s) in Quran in Abdullah Yusuf Ali translation.

(31) To Him will be your return- of all of you. The promise of Allah is true and sure. It is He Who beginneth the process of creation, and repeateth it, that He may reward with justice those who believe and work righteousness; but those who reject Him will have draughts of boiling fluids, and a penalty grievous, because they did reject Him.

(32) Moses prayed: "Our Lord! Thou hast indeed bestowed on Pharaoh and his chiefs splendour and wealth in the life of the present, and so, Our Lord, they mislead (men) from Thy Path. Deface, our Lord, the features of their wealth, and send hardness to their hearts, so they will not believe until they see the grievous penalty."

(33) Even if every Sign was brought unto them,- until they see (for themselves) the penalty grievous.

(34) "That ye serve none but Allah: Verily I do fear for you the penalty of a grievous day."

(35) The word came: "O Noah! Come down (from the Ark) with peace from Us, and blessing on thee and on some of the peoples (who will spring) from those with thee: but (there will be other) peoples to whom We shall grant their pleasures (for a time), but in the end will a grievous penalty reach them from Us."

(36) Such is the chastisement of thy Lord when He chastises communities in the midst of their wrong: grievous, indeed, and severe is His chastisement.

(37) So they both raced each other to the door, and she tore his shirt from the back: they both found her lord near the door. She said: "What is the (fitting) punishment for one who formed an evil design against thy wife, but prison or a grievous chastisement?"

(38) And Satan will say when the matter is decided: "It was Allah Who gave you a promise of Truth: I too promised, but I failed in my promise to you. I had no authority over you except to call you but ye listened to me: then reproach not me, but reproach your own souls. I cannot listen to your cries, nor can ye listen to mine. I reject your former act in associating me with Allah. For wrong-doers there must be a grievous penalty."

(39) And that My Penalty will be indeed the most grievous Penalty.

(40) Let them bear, on the Day of Judgment, their own burdens in full, and also (something) of the burdens of those without knowledge, whom they misled. Alas, how grievous the burdens they will bear!