nascency
A state of incipiency; a quality of nascence.
countable, uncountable
[W]e are, therefore, sure in advance, of being right, if we say of any perception that first it didn't exist, and that then there was a mere suggestion and nascency of it, which grew more definite, until, at last, the thing itself was fully established.
Where it comes from
Learned borrowing from Latin nāscentia. Doublet of nascence.
Adapted from the Wiktionary entry nascency (CC BY-SA 4.0).