Valmiki Ramayana Ayodhya Kanda Sarga 23 Shloka 2
Original Shlokaतदा तु बध्द्वा भ्रुकुटीं भ्रुवोर्मध्ये नरर्षभः। निशश्वास महासर्पो बिलस्थ इव रोषितः।।2.23.2।।
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नरर्षभः best among men (Lakshmana), तदा तु then, भ्रुवो: brows, मध्ये in between, भ्रुकुटीम् a frown, बध्द्वा having knitted, बिलस्थः in its hole, रोषितः seized with anger, महासर्पः great serpent, इव like, निशश्वास hissed.
Lakshmana, frowning between his eyebrows, hissed like a great serpent seized with anger in its hole.