Southward means towards the warmer half of the world. Head southward, southward migration, the southward slope.
Southwards with the s is the commoner adverb in Britain, and southward the adjective. A southward-facing slope in the northern hemisphere gets the sun, which is why vineyards face that way.
1adverbsouthwardTowards the warmer half of the world.
“The geese fly southward every autumn to escape the cold.”
southward is a direction.
Middle English
south
English
south
English, today
southward
From south + -ward. south comes from Middle English south. From Middle English south, from Old English sūþ, from Proto-West Germanic sunþr (“southern”), from Proto-Germanic sunþrą (“south”), from Proto-Indo-European sóh₂wl̥ (“sun”). 2
Etymology from Wiktionary, CC BY-SA