The word(s) "severest" appears 3 time(s) in 3 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Then those who reject Faith in the Signs of Allah will suffer the severest penalty, and Allah is Exalted in Might, Lord of Retribution.

(سورة آل عمران, Aal-i-Imraan, Chapter #3, Verse #4)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) A little enjoyment in this world!- and then, to Us will be their return, then shall We make them taste the severest penalty for their blasphemies.

(سورة يونس, Yunus, Chapter #10, Verse #70)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(3) In front of the Fire will they be brought, morning and evening: And (the sentence will be) on the Day that Judgment will be established: "Cast ye the People of Pharaoh into the severest Penalty!"

(سورة غافر, Ghafir, Chapter #40, Verse #46)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)