Valmiki Ramayana Yuddha Kanda Sarga 90 Shloka 36
Original Shlokaतमसापिहितंसर्वमासीत्प्रतिभयंमहत् । अस्तंगतेसहस्रांशेसम्वृतेतमसा च वै ।।6.90.36।। रुधिरौघामहानद्यःप्रावर्तन्तसहस्रशः ।
1 source checked for this shloka
सर्वम् everything, तमसा darkness, पिहितम् enveloped, महत् great, प्रतिभयम् dreadful appearance, आसीत् exists, सहस्रांशो thousand rays, अस्तंगते sinks down, तमसा darkness, सम्वृते envelops, सहस्रशः thousands, रुधिरौघमहानद्यः blood streams, प्रावर्तन्त flowed
As the sun sank down, darkness enveloped, everything was dark and dreadful in appearance. Streams of blood of thousands flowed.