[thee-uh-rahyz, theer-ahyz]

verb (used without object), the·o·rized, the·o·riz·ing.

to form a theory or theories.

verb (used with object), the·o·rized, the·o·riz·ing.

to form a theory or theories about.

Also especially British, the·o·rise.

Origin of theorize

From the Medieval Latin word theōrizāre, dating back to 1630–40. See theory, -ize
Related formsthe·o·ri·za·tion, nounthe·o·riz·er, nouno·ver·the·o·ri·za·tion, nouno·ver·the·o·rize, verb (used without object), o·ver·the·o·rized, o·ver·the·o·riz·ing. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for theorise

Historical Examples of theorise

  • Of course I can theorise it now perfectly, and practise it at periods.

    The Hive

    Will Levington Comfort

  • You must acquire all the facts, before you can be qualified to theorise.

  • I must sprawl and flounder, comment and theorise, if I am to get the thing out I have in mind.

    Tono Bungay

    H. G. Wells

  • We can all theorise, and lay down the law; the tug comes when we begin to act.

    Lady Cassandra

    Mrs George de Horne Vaizey

  • But it is unlikely that he attempted to theorise further on the nature of the power.

    Oxford Lectures on Poetry

    Andrew Cecil Bradley

British Dictionary definitions for theorise




(intr) to produce or use theories; speculate
Derived Formstheorization or theorisation, nountheorizer or theoriser, noun
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

Word Origin and History for theorise



1630s, perhaps a formation in English from theory + -ize. Related: Theorized; theorizing.

Online Etymology Dictionary, © 2010 Douglas Harper