Illustrated Companion to the Latin Dictionary/Atriolum

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich. 

ATRI'OLUM. Diminutive of Atrium, and thus, in a general sense, any small atrium; but the word has also a more special application, and designates a distinct member in the large Roman palaces, which might be styled the second or back atrium; for it was disposed with sleeping rooms and other members all round it, similar to those of the principal one, from which it chiefly differed in size, and perhaps in splendour. Cic. Q. Fr. iii. 1. 1. Id. Att. i. 10.