The child was so frightened he wouldn't stop trembling.
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Literary. Modern speech prefers 哆嗦 (duōsuo) or 发抖 (fādǒu). 瑟索 shows up in fiction, especially Lu Xun-era prose, and in lyrics aiming for a cold, lonely feel.
memory
Same 瑟 as in 萧瑟 (xiāosè, 'rustling and bleak') — both onomatopoeic-rooted words for the chilly hush before winter. Hearing 瑟索 should evoke autumn wind through bare branches.
