Valmiki Ramayana Yuddha Kanda Sarga 7 Shloka 10
Original Shlokaदानवेन्द्रोमधुर्नामवीर्योत्सिक्तोदुरासदः । विगृह्यवशमानीतःकुम्भीनस्याःसुखावहः ।।6.7.10।।
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दुरासदः difficult to approach, वीर्योत्सिक्तो: proud of his valour, कुम्भीनस्याः Kumbhinasi (your sister), सुखावहः who brings joy to her (who is husband of), दानवेन्द्रो: ruler of Danavas, मधुर्नाम: called as Madhu, विगृह्य: offering to fight and win, वशमानीतः subjugated to you.
"Madhu, another ruler of Danavas who was proud of his valour and difficult to approach, the husband of Kumbhinasi was subjugated by you by your offering to fight with him."