A branch coming out of a trunk. The new part was not stuck on from outside — it pushed out of the thing it belongs to, and it is still joined to it, so you can put a finger on the join and follow it back. Hold that one picture and the abstract use follows without any extra work: a club, a rule, a business, a problem can all come out of something earlier in exactly the same way, still attached, still traceable.
可以想成一根從樹幹長出來的枝子。那一段不是從外面黏上去的，是從本體推出去的，而且到現在還連著，你的手指按得到接點，也順得回去。抓住這一個畫面，抽象的用法就自己跟上來了：一個社團、一條規定、一門生意、一個問題，都可能用同樣的方式從更早的東西長出來——還連著，也還找得到來源。
From the word’s history
From out- (outwards) plus growth, giving the plain meaning a thing that has grown outwards.
來自 out-（向外）加上 growth（生長），字面就是「向外長出來的東西」。
Wiktionary entry for outgrowth (kaikki:3f6f69a190036ae4:1337717892), etymology section supplied in the evidence packet
登入就可以看每一支怎麼連回核心畫面。