China: by Han scholar Xu Shen
Supersedes the more basic first known Chinese dictionary, the Erya (200s BCE) [author unknown].
The Shuowen Jiezi is a sophisticated early second century Chinese dictionary (from the Han Dynasty). It is ultimately presented to Emperor An (of Han) by Xu Chong, the son of Xu Shen, two decades later, in 121 CE.
Timing is apparently everything.