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aperiodic

[ey-peer-ee-od-ik]
adjective
  1. not periodic; irregular.
  2. Physics. of or relating to vibrations or oscillations with no apparent period.

Origin of aperiodic

First recorded in 1875–80; a-6 + periodic1
Related formsa·pe·ri·od·i·cal·ly, adverba·pe·ri·o·dic·i·ty [ey-peer-ee-uh-dis-i-tee] /eɪˌpɪər i əˈdɪs ɪ ti/, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for aperiodic

aperiodic

adjective
  1. not periodic; not occurring at regular intervals
  2. physics
    1. (of a system or instrument) being damped sufficiently to reach equilibrium without oscillation
    2. (of an oscillation or vibration) not having a regular period
    3. (of an electrical circuit) not having a measurable resonant frequency
Derived Formsaperiodically, adverbaperiodicity (ˌeɪpɪərɪəˈdɪsɪtɪ), 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 aperiodic
adj.

1874, from a- (2), privative prefix, + periodic.

Online Etymology Dictionary, © 2010 Douglas Harper
aperiodic in Medicine

aperiodic

[ā′pîr-ē-ŏd′ĭk]
adj.
  1. Not occurring periodically.
Related formsa′pe•ri•od′i•cal•ly adv.a•pe′ri•o•dic′i•ty (-ə-dĭs′ĭ-tē) n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.