核心畫面
Picture two people leaning against each other with no wall behind either of them. From the outside it looks like support. In fact neither one can stand up straight, because the moment one of them does, the other falls. That is the shape the word draws: co- for together, dependent for leaning, and a pair who are holding each other up and holding each other down at the same time.
可以想成兩個人互相靠著站，背後都沒有牆。從外面看像是互相扶持。其實誰也站不直，因為只要有一個人站起來，另一個就會倒。…更多收起
可以想成兩個人互相靠著站，背後都沒有牆。從外面看像是互相扶持。其實誰也站不直，因為只要有一個人站起來，另一個就會倒。co-（一起）加 dependent（依賴的）畫的就是這個姿勢：兩個人同時撐著對方，也同時壓著對方。From the word’s history
Wiktionary gives the word as co- + dependent, with co- coming through Latin con-, meaning together or with. The parts still say exactly what the word means: leaning, together.
Wiktionary 記的來源是 co- 加 dependent，co- 經由拉丁文 con- 而來，意思是「一起、共同」。這兩個部件到今天還是字面上的意思：一起靠著。
Wiktionary entry for co-dependent, kaikki extract supplied in this packet (source_ref kaikki:3f6f69a190036ae4:1293906565): From co- + dependent; Latin con- > co-.