The word(s) "grievous" appears 33 time(s) in 33 verse(s) in Quran in Muhammad Habib Shakir translation.

(21) When you received it with your tongues and spoke with your mouths what you had no knowledge of, and you deemed it an easy matter while with Allah it was grievous.

(22) Surely (as for) those who love that scandal should circulate respecting those who believe, they shall have a grievous chastisement in this world and the hereafter; and Allah knows, while you do not know.

(23) Surely those who accuse chaste believing women, unaware (of the evil), are cursed in this world and the hereafter, and they shall have a grievous chastisement.

(24) Surely I fear for you the chastisement of a grievous day

(25) And do not touch her with evil, lest the punishment of a grievous day should overtake you.

(26) But they called him a liar, so the punishment of the day of covering overtook them; surely it was the punishment of a grievous day.

(27) And when Luqman said to his son while he admonished him: O my son! do not associate aught with Allah; most surely polytheism is a grievous iniquity--

(28) O you who believe! do not enter the houses of the Prophet unless permission is given to you for a meal, not waiting for its cooking being finished-- but when you are invited, enter, and when you have taken the food, then disperse-- not seeking to listen to talk; surely this gives the Prophet trouble, but he forbears from you, and Allah does not forbear from the truth And when you ask of them any goods, ask of them from behind a curtain; this is purer for your hearts and (for) their hearts; and it does not behove you that you should give trouble to the Apostle of Allah, nor that you should marry his wives after him ever; surely this is grievous in the sight of Allah.

(29) Say: I fear, if I disobey my Lord, the chastisement of a grievous day.

(30) Before them is hell, and there shall not avail them aught of what they earned, nor those whom they took for guardians besides Allah, and they shall have a grievous punishment.