Valmiki Ramayana Yuddha Kanda Sarga 59 Shloka 15
Original Shlokaयोऽसौरथस्थोमृगराजकेतुर्दून्वस्थिन्दनुश्शक्रधनुःप्रकाशम् । करीवभात्युग्रविवृत्तदंष्ट्रस्सइन्द्रजिन्नामवरप्रधानः ।।6.59.15।।
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रथस्थः from the chariot, मृगराजकेतुः distinguished by the sign of lion, शक्रधनुःप्रकाशम् splendid as the bow of Indra, धनुः bow, धुन्वन् making sound, यःअसौ he who, उग्रविवृत्तदंष्ट्रः with terrific teeth projected forward, करीव elephant, भाति looks like, सः he, वरप्रधानः eminent by the boons bestowed, इन्द्रजित् नाम Indrajith by name.
"The one on the chariot, distinguished by the sign of a lion, and making sound with his bow, splendid as Indra's bow with terrific teeth projected forward looks like an elephant, eminent by virtue of the boons bestowed is Indrajith by name."