noun
well-informed person; insider; someone in the know
Refers to a person who is knowledgeable about a particular matter or situation, often implying inside information or familiarity with the background. Can also be used attributively to describe such a person.
See also: 通
彼はこの業界の事情通だ。
He is an insider in this industry.
事情通の話によると、来
According to someone in the know, there will be a big announcement next month.