new-sprung vs newborn

new-sprung is not a noun while newborn is a noun.

Word	Noun	Adjective	Verb	Adverb
new-sprung	No	Yes	No	No
newborn	Yes	Yes	No	No

As adjectives, new-sprung and newborn are synonyms defined as:

new-sprung and newborn: having just or recently arisen or come into existence

new-sprung (noun)	newborn (noun)
	a baby from birth to four weeks

new-sprung (adjective)	newborn (adjective)
having just or recently arisen or come into existence	having just or recently arisen or come into existence
	recently born