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sporadic

[spuh-rad-ik]
adjective
  1. (of similar things or occurrences) appearing or happening at irregular intervals in time; occasional: sporadic renewals of enthusiasm.
  2. appearing in scattered or isolated instances, as a disease.
  3. isolated, as a single instance of something; being or occurring apart from others.
  4. occurring singly or widely apart in locality: the sporadic growth of plants.
Sometimes spo·rad·i·cal.

Origin of sporadic

1680–90; < Medieval Latin sporadicus < Greek sporadikós, equivalent to sporad- (stem of sporás strewn, akin to sporá spore) + -ikos -ic
Related formsspo·rad·i·cal·ly, adverbspo·rad·i·cal·ness, nounspo·ra·dic·i·ty [spawr-uh-dis-i-tee, spohr-] /ˌspɔr əˈdɪs ɪ ti, ˌspoʊr-/, spo·ra·dism, noun

Synonyms for sporadic

3. separate, unconnected.

Antonyms for sporadic

1. continuous.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for sporadicity

sporadic

adjective
  1. occurring at irregular points in time; intermittentsporadic firing
  2. scattered; isolateda sporadic disease
Derived Formssporadically, adverbsporadicalness, noun

Word Origin for sporadic

C17: from Medieval Latin sporadicus, from Greek sporadikos, from sporas scattered; related to Greek speirein to sow; see spore
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 sporadicity

sporadic

adj.

1650s (implied in sporadical), from Medieval Latin sporadicus "scattered," from Greek sporadikos "scattered," from sporas (genitive sporados) "scattered," from spora "a sowing" (see spore). Originally a medical term, "occurring in scattered instances;" the meaning "happening at intervals" is first recorded 1847. Related: Sporadically.

Online Etymology Dictionary, © 2010 Douglas Harper
sporadicity in Medicine

sporadic

[spə-răd′ĭk, spô-]
adj.
  1. Occurring at irregular intervals.
  2. Occurring singly; not grouped.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.