Stand in front of something and ask one question: did this come about on its own, or did people put it here? Man-made is the answer on the second side. The word is a small label you stick on a thing to say that a human hand is somewhere behind it.
man (meaning people, not only men) + made. First recorded in 1615; the older pronunciation put the main stress on man.
man（這裡指人類，不是只有男性）加上 made（做出來的）。資料記錄最早出現在一六一五年，而且比較早的唸法是把主重音放在 man 上。字面上就是「人做的」，這也正是它今天全部用法的來源。
Wiktionary (kaikki extract) etymology for man-made adj, source_ref kaikki:3f6f69a190036ae4:1016449018:10397 (cites OED for the stress note)
One branch
人做的，不是自然來的
兩個意思其實是同一張標籤，差別只在你把它貼在什麼上面：貼在材料上，還是貼在一整樣東西或一個情況上。
adjective · B1
Made or caused by people, rather than happening through nature on its own — used about things like lakes, islands and hills, and about problems and situations that people have brought about.
人為的；人工的