southward spread

基本解释

At a later date the cultivation of cocoa spread southward, mainly to Brazil, and at the end of the last century, spread to the equatorial regions of West Africa.
之后，可可的种植向南扩张。主要扩展到了巴西。上个世纪末，可可种植扩张到了西非赤道区。
chengluochenzhong.blog.163.com
About 138 BC, all the Wusun migrated westward to the Ili river valley and rebuilt the state there. Later, the rest of the Wusun spread southward to the Cong Ling Ridges (the Pamirs).
公元前138年左右，乌孙举族西迁至伊犁河谷周围重新建国，此后其余部又向南方的葱岭（帕米尔高原）内外扩散。
Marine transgression and sea flooding happened many times along the embayment from east to west, and the sea water spread north and southward and even probably westward from Jixi Basin.
多次海侵和海泛沿着这一海湾由东向西至鸡西后向南和向北，并可能向西扩散。

The disease has spread from eastern China both northward and southward, leading to the closure of a growing number of markets where live chicken is sold as a preventative measure.
FORBES: China H7N9 Bird Flu Cases Rise By Five; Four Provinces Report Illnesses In One Day

南传
"The Southward spread of Taoism" means the spread of Taoism founded in the area north of Wuling(五岭 ) to Lingnan ( 岭南 ), south of Wuling.
“道教南传”是指在岭北(以五岭为界)创立的道教向岭南的传播。