欸
Definition
ǎi:* 〔～乃〕象声词，指摇橹声，如"烟销日出不见人，～～一声山水绿"。 ēi:* 叹词，表示招呼。 ～，你快来！ éi:* 叹词，表示诧异。 ～，他怎么又走了？ ěi:* 叹词，表示不以为然。 ～，你这话可不对呀！ èi:* 叹词，表示应声或同意。 ～，我就来！
sigh; an exclamatory sound
Structure
Related substructures
Precursors
Small Seal Script
Standardized 221–206 BCE (Qin); developed earlier in Qin
The standardized seal script promulgated after Qin’s unification, based on earlier Qin seal forms and used as an empire-wide norm.Wikipedia ->
Transmitted Pre-Qin Forms
Pre-Qin forms (≤221 BCE) / late 2nd century BCE onward (Han → later textual transmission)
Pre-Qin character forms preserved through later textual transmission (often discussed as the 'Old Text' / guwen tradition). Shaped by repeated copying, they can diverge from excavated Warring States materials.Wikipedia ->
Liushutong Seal Forms
Pre-Qin to Han seal-type forms (≤220 CE) / compiled 1661 (Min Qiji); collated and printed 1720 (Bi Hongshu)
A ten-volume compendium of seal-script variants arranged by the rhymes of Hongwu Zhengyun: each head character gives its Shuowen small seal form, then variants gathered from guwen, zhouwen, bronze inscriptions and Qin–Han seals. Long a standard reference for seal carvers, but the forms are compiled rather than excavated and were collected with little vetting, so many are of doubtful authenticity.Wikimedia Commons ->