The word(s) "gentleness" appears 2 time(s) in 2 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Strain not thine eyes. (Wistfully) at what We have bestowed on certain classes of them, nor grieve over them: but lower thy wing (in gentleness) to the believers.

(سورة الحجر, Al-Hijr, Chapter #15, Verse #88)
(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) And those that flow with ease and gentleness;

(سورة الذاريات, Adh-Dhaariyat, Chapter #51, Verse #3)
(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)