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English definition of “infinitesimal”

infinitesimal

adjective     /ˌɪn.fɪ.nɪˈtes.ɪ.məl/ formal
extremely small: The amounts of radioactivity present were infinitesimal.Extremely smallSmall infinitesimally     /-mə.li/ adverb infinitesimally smallExtremely smallSmall
(Definition of infinitesimal adjective from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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