south-southeast vs sou'-sou'-east

south-southeast is not a noun while sou'-sou'-east is a noun.

Word	Noun	Adjective	Verb	Adverb
south-southeast	No	No	No	Yes
sou'-sou'-east	Yes	No	No	Yes

As adverbs, south-southeast and sou'-sou'-east are synonyms defined as:

south-southeast and sou'-sou'-east: to, toward, or in the south southeast

south-southeast (noun)	sou'-sou'-east (noun)
	the compass point midway between south and southeast

south-southeast (adverb)	sou'-sou'-east (adverb)
to, toward, or in the south southeast	to, toward, or in the south southeast