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

(1) And for those who launch a charge against their spouses, and have (in support) no evidence but their own,- their solitary evidence (can be received) if they bear witness four times (with an oath) by Allah that they are solemnly telling the truth;

(سورة النور, An-Noor, Chapter #24, Verse #6)
(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) For they said: "What! a man! a solitary one from among ourselves! shall we follow such a one? Truly should we then be straying in mind, and mad!

(سورة القمر, Al-Qamar, Chapter #54, Verse #24)
(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)