Origin; source; derivation — the history or background from which something comes.
この地名の由来を調べてみた。
I looked into the origin of this place name.
伝統行事の由来を子どもたちに教えた。
I taught the children the history/origin of the traditional event.
名前の由来を聞いて驚いた。
I was surprised when I heard the origin of the name.
Originally; by nature; from the start — adverbial use that is somewhat literary or formal.
由来、本来は別の目的で作られた施設だ。
Originally, the facility was built for a different purpose.
由来、この仕事は細かい作業が多い。
By nature, this job involves a lot of detailed work.