1. Plural of atheneum: a literary or scientific institution, society, or reading room, typically one open to the public or members.
Usage: Often capitalized when referring to a specific named institution; Chiefly historical or formal

Examples

• The city's atheneums served as important centers for intellectual exchange in the 19th century.
• Several atheneums in New England were founded to promote education and culture among their members.
• The Providence Athenaeum and the Boston Athenaeum are among the oldest atheneums in the United States.
• Members of the atheneums could borrow books and attend lectures on literature and science.
• Many historic atheneums have been preserved as cultural landmarks.