Source, Origin, Foundation
Noun and の adjective
こんぽん
ねもと
そもそも、根本から間ちがってるんだよ。
First of all, you are fundamentally wrong.
そのふうふは、子どもの教育についての根本の考え方が合わなかったんです。
That couple had fundamentally different ideas about their kid's education.
クリステンはベーコンを食べませんが、この問題の根本の原因はどこにあると思いますか？
Kristen doesn’t eat bacon; where do you think the root of this problem lies?
The root origin is the root of something. Possibly even more root than root, but we'll stick with root.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Careful, 本 is ぽん, which is a weird rendaku.