What is "fangyan"

The Fāngyán (; literally meaning "regional speech") was the first Chinese dictionary of dialectal terms. It was edited by the scholar Yang Xiong, who lived from 53 BC to 18 AD. The full title is Yóuxuān shǐzhĕ juédài yǔ shì biéguó fāngyán (輶軒使者絕代語釋別國方言) "Local speeches of other countries in times immemorial explained by the Light-Carriage Messenger," which alludes to a Zhou dynasty tradition of imperial emissaries who made annual surveys of regional vocabulary throughout China. Yang's preface explains that he spent 27 years collating and editing the Fangyan, which has some 9000 characters in 13 chapters (卷).

Fangyan definitions typically list regional synonyms. For instance, chapter 8, which catalogs animal names, gives regional words for hu (虎 "tiger") in Han times.

(虎, 陳魏宋楚之間或謂之李父, 江淮南楚之間謂之李耳, 或謂之於菟. 自關東西或謂之伯都.) "Tiger: in the regions of Chen-Wei Song-Chu [Central China], some call it lifu; in the regions of Jiang-Huai Nan-Chu [Southern China], they call it li'er, and some call it wutu. From the Pass, east- and west-ward [Eastern and Western China], some call it also bodu." (adapted from Serruys 1967: 256)

Comparative linguists have used dialect data from the Fangyan in reconstructing how Chinese was pronounced during the 1st century CE, which is an important diachronic stage between Old Chinese and Middle Chinese. In the above example, Serruys reconstructs "tiger" as Old Chinese *blxâg.