Picture a room nobody has cared about for years: black marks behind the sink, a window that will not open, things left where they fell. You would not want to sit down in it. English keeps that feeling and points it at other things — at what a person did, and at how a person holds on to money. In every use, the word is the speaker back from something that feels unclean.
From Middle English sordide, from Latin sordidus, from sordeō and sordēs, meaning dirt or filth; possibly also by way of French sordide. The literal dirt is the oldest layer, and the moral uses grow out of it.
這個字來自中古英文 sordide，再往前是拉丁文 sordidus，出自 sordēs，意思就是髒污；也可能經過法文 sordide。所以真正的髒是最早的那一層，講品行、講貪財的用法都是從它長出來的。
Wiktionary entry for sordid (packet source_ref kaikki:3f6f69a190036ae4:715370979:25335)
From the picture
行為上的髒
把「不想靠近」這個感覺從房間搬到行為上。事情本身看不見摸不著，但說話的人對它的反應，跟看到那個髒房間是同一種。
adjective · C1
Describing behaviour that is dishonest or morally low, usually about money, cheating or something people would rather keep hidden. The word shows the speaker's clear disgust at what was done.
骯髒下流的；不光彩的
adjective · C1
Very dirty, untidy and unpleasant to be in. It is usually said about a room, a building or a street that has been left in a bad state for a long time.
髒亂破敗的