noun
worldly wisdom; knowledge of the ways of the world
Refers to practical social intelligence gained through life experience, not academic knowledge.
彼は若いが、世間知に長けている。
He is young, but he has a lot of worldly wisdom.
世間知のない行動で、周りを困らせてしまった。
My naive behavior caused trouble for those around me.
世渡り focuses on the skill of getting along in society, often with a nuance of tact or shrewdness, while 世間知 is more about accumulated practical knowledge of how the world works.
常識 is common sense or general knowledge expected of any adult, whereas 世間知 implies deeper, experience-based understanding of social norms and human nature.
Compound of 世間 (world, society) and 知 (knowledge, wisdom). The exact historical derivation is uncertain, but the word transparently means 'knowledge of the world'.