If you describe something as seamy, you mean that it involves unpleasant aspects of life such as crime, sex, or violence.
例句
...Hamburg's seamy St Pauli's district.漢堡骯臟污穢的圣保利街區(qū)...the seamier side of life.生活較丑惡的一面
英漢詞典釋義
adj.
(生活等的)丑陋的一面，陰暗面
It’s well known that the world of entertainment has its seamy side: drug abuse, corruption, alcoholism …眾所周知，演藝界有其骯臟的一面：濫用毒品、墮落腐化、酗酒等等。
英英詞典釋義
Adjective
1. morally degraded;
"a seedy district""the seamy side of life""sleazy characters hanging around casinos""sleazy storefronts with...dirt on the walls"- Seattle Weekly"the sordid details of his orgies stank under his very nostrils"- James Joyce"the squalid atmosphere of intrigue and betrayal"