noun
magazine publisher; magazine company
Refers to the company or firm that publishes a magazine, not the magazine itself.
彼は大手の雑誌社に勤めている。
He works for a major magazine publisher.
新聞社 is a newspaper company, whereas 雑誌社 is a magazine company.
Compound of 雑誌 (ざっし, 'magazine') and 社 (しゃ, 'company').