club for working adults
Refers to hobby or activity clubs whose members are primarily working adults, as opposed to university student circles. Often used in contrast to 大学サークル.
See also: サークル
社会人サークルでテニスを始めました。
I started playing tennis at a club for working adults.
週末は社会人サークルのバスケに参加しています。
On weekends I join the basketball club for working adults.
A university club or circle. 社会人サークル is its adult counterpart, typically with more flexible schedules and a wider age range.
Compound of 社会人 (working adult) and サークル (club/circle). The term became common as more adults sought hobby communities outside of work.