society; social circles
Refers to the social world or one's social environment, often with a nuance of the company one keeps or the social scene one moves in.
He has a wide social circle.
Learn the rules of social circles.
社会 is the general word for 'society' as a whole, while 交際社会 specifically refers to the social world of personal relationships and socializing.
社交界 also means 'social circles' or 'high society', but often carries a more formal or upper-class nuance compared to 交際社会.
Compound of 交際 (こうさい, 'association, socializing') and 社会 (しゃかい, 'society'). The exact historical derivation is uncertain, but the combination straightforwardly yields the meaning 'social circles' or 'the society one associates with'.