See more synonyms for externality on Thesaurus.com
noun, plural ex·ter·nal·i·ties.
  1. the state or quality of being external.
  2. something external; an outward feature.
  3. excessive attention to externals.
  4. an external effect, often unforeseen or unintended, accompanying a process or activity: to eliminate externalities such as air pollution through government regulation.

Origin of externality

First recorded in 1665–75; external + -ity
Related formsnon·ex·ter·nal·i·ty, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for externality

Historical Examples of externality

British Dictionary definitions for externality


noun plural -ties
  1. the state or condition of being external
  2. something external
  3. philosophy the quality of existing independently of a perceiving mind
  4. an economic effect that results from an economic choice but is not reflected in market prices
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 externality

1713, from external + -ity.

Online Etymology Dictionary, © 2010 Douglas Harper