Definition of infinitesimal in English:

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Pronunciation: /ˌinfinəˈtes(ə)m(ə)l/


Extremely small: an infinitesimal pause
More example sentences
  • I seek leave to table from the New England Journal of Medicine a recent definitive study showing that intellectual impairment of children can occur even with extremely infinitesimal amounts of lead.
  • It was a pause so infinitesimal that I almost didn't catch it, but I knew what I glimpsed.
  • Minute, infinitesimal amounts of chemical contaminants crossing the placenta can cause cancer in young adults decades later.
minute, tiny, minuscule, very small;
informal teeny, wee, teeny-weeny, itsy-bitsy, little-bitty


An indefinitely small quantity; a value approaching zero.
Example sentences
  • These two concepts, infinitesimals and infinite quantities, however, were stirring great philosophical dilemmas.
  • The book shows how this notion can be used to form various kinds of infinities such as the projective plane, transfinite numbers, and infinitesimals.
  • Also in 1786 he again worked on his ideas for the differential and integral calculus, giving a new treatment of infinitesimals.


Although this long word is commonly assumed to refer to large numbers, infinitesimal describes only very small size. While there may be an infinite number of grains of sand on the beach, a single grain may be said to be infinitesimal.



Pronunciation: /ˌinˌfinəˈtes(ə)m(ə)lē/
Example sentences
  • The design of the pipeline means that the risk of such an event or any other type of gas escape is infinitesimally small.
  • In fact, leaving aside the infinitesimally small world of math geniuses, there isn't any evidence that men are more intelligent than women, and no one seriously says so.
  • At their best they became monolithic tomes - bunkers for content, guides updated haphazardly that infinitesimally accrete ‘content’.


Mid 17th century: from modern Latin infinitesimus, from Latin infinitus (see infinite), on the pattern of centesimal.

Words that rhyme with infinitesimal


For editors and proofreaders

Syllabification: in·fin·i·tes·i·mal

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