Primarily, Essentially, Naturally
Noun and の adjective
ほんらい
このサイトは本来かめのせいそくちとしてつかわれていた。
This site was originally used as a turtle habitat.
その言ばの本来のいみをしっていますか。
Do you know the original meaning of that word?
本来漢字は悪いものではない。
Kanji in and of itself isn’t a bad thing.
You want to talk about the origin where something comes from. That's where it is from originally.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.