Where does “nub” come from?

I appreciate the detailed instructions, but I notice there's a significant problem: the etymology chain provided traces "newbie/new/-y/-ie/-ia" but the headword is "nub," which is a completely different word. These don't match. Could you provide the correct etymology chain for "nub"? Once I have the accurate linguistic ancestry for this headword, I'll write the one-sentence summary following all your specifications.

nub (English): The innermost section of a chrysalis in a silk...

Definitions

  1. The innermost section of a chrysalis in a silk...

Ancestry of “nub”, step by step

StepLanguageWordMeaning
1EnglishnoobA newb or newbie; refers to the idea that someone...
2EnglishnewbieA newcomer, someone new to something; A new user...
3EnglishnewieSomething newly released, such as a song or film
4EnglishNewmade, or created
5EnglishMANInitialism of Metropolitan Area Network
6EnglishmanualA handbook; A booklet that instructs on the usage...
7Middle Englishmanuel
8Anglo-Normanmanuelmanual; done with the hands; handle; manual;...
9Old Frenchmanual
10Latinmanuālishand
11Latinmanushand; bravery, valor; violence, fighting
12Proto-Italicmanushand
13Proto-Indo-Europeanman-human being; man; hand

Words derived from “nub

Every word from Proto-Indo-European man-