[ tree-tis ]
/ ˈtri tɪs /


a formal and systematic exposition in writing of the principles of a subject, generally longer and more detailed than an essay.

Origin of treatise

1300–50; Middle English tretis < Anglo-French tretiz, akin to Old French traitier to treat Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for treatise

British Dictionary definitions for treatise

/ (ˈtriːtɪz) /


a formal work on a subject, esp one that deals systematically with its principles and conclusions
an obsolete word for narrative

Word Origin for treatise

C14: from Anglo-French tretiz, from Old French tretier to treat
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012