We don't have synonyms for jiangnan yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are xiangtan, siangtan and jiangmen.
(n) :
A roughly defined area of China always including the lands south of the lower reaches of the Yangtze in Shanghai, southern Jiangsu, and northern Zhejiang, sometimes inclusive of its cultural sphere north of the river and sometimes extending south as far as Guangdong.
(n) :
(historical) A province of Qing-era China, now divided into Jiangsu and Anhui.
(n) :
A roughly defined area of China always including the lands south of the lower reaches of the Yangtze in Shanghai, southern Jiangsu, and northern Zhejiang, sometimes inclusive of its cultural sphere north of the river and sometimes extending south as far as Guangdong.
(n) :
(historical) A province of Qing-era China, now divided into Jiangsu and Anhui.