[ ek-ster-nal-i-tee ]
/ ˌɛk stərˈnæl ɪ ti /

noun, plural ex·ter·nal·i·ties.

the state or quality of being external.
something external; an outward feature.
excessive attention to externals.
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

OTHER WORDS FROM externality

non·ex·ter·nal·i·ty, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for externality

British Dictionary definitions for externality

/ (ˌɛkstɜːˈnælɪtɪ) /

noun plural -ties

the state or condition of being external
something external
philosophy the quality of existing independently of a perceiving mind
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