spo·rad·ic (spə-rădĭk, spô-)
1. Occurring at irregular intervals or in isolated or scattered places; having no pattern or order: his sporadic attendance in class; rebels who put up sporadic resistance. See Synonyms at periodic.
2. Medicine Not epidemic, endemic, or inherited. Used of a disease or condition: Most cancers are sporadic, caused by genetic mutations that are not heritable.
[Medieval Latin sporadicus, scattered, from Greek sporadikos, from sporas, sporad-; see sper- in the Appendix of Indo-European roots.]
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.