Definition of infinitesimal in English:



  • Extremely small.

    ‘an infinitesimal pause’
    • ‘There are infinitesimal numbers of cycles of improvement and degradation, one following the other like the phases of waxing and waning moons.’
    • ‘There was an infinitesimal pause before the last word, as the principal tactfully searched for the right word, but an untrained ear wouldn't have noticed it.’
    • ‘I don't have an explanation - I'd like to have one but I don't - but in the meantime, without evidence, the odds of your position being right are so infinitesimal as to be irrelevant.’
    • ‘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.’
    • ‘Any way you look at it, the number is infinitesimal.’
    • ‘So, living in London and desperately weak of will, you get poisoned by choice; overwhelming and almost infinitesimal choice.’
    • ‘But the new puritans argue that any risk, no matter how infinitesimal, is intolerable.’
    • ‘It is fair to say that in the entire North Western area that the level of infrastructural investment has been infinitesimal in comparison to spending on the east coast.’
    • ‘And that's critical to the analysis of the solar wind, the particles of which contain infinitesimal traces of the 83 naturally occurring elements.’
    • ‘Minute, infinitesimal amounts of chemical contaminants crossing the placenta can cause cancer in young adults decades later.’
    • ‘The rock is already slipping down by infinitesimal degrees.’
    • ‘Really, what I want to do is impossible, for any listing of an endless series is doomed to be infinitesimal.’
    • ‘There isn't a single person in all these millions, including the president of the pencil company, who contributes more than a tiny, infinitesimal bit of know-how.’
    • ‘Or maybe, we fear that if we pause for even an infinitesimal second, someone else will grab our place and get ahead?’
    • ‘For whatever infinitesimal consolation it may offer, Wellstone could feel the victory coming.’
    • ‘But now, increasingly, those infinitesimal aspects of everyday life, taken together, are seen to have a broader importance and even might be the keys to a certain kind of political action or subversion.’
    • ‘He blinked and rapidly adjusted the viewer's dials, but what seemed to be a tiny, almost infinitesimal flashing green light on one end of the diamond, did not disappear.’
    • ‘The changes in timing a hit are almost laughably infinitesimal but are utterly crucial to the way the foil is used.’
    • ‘People worry more about infinitesimal risks they feel are imposed on them than they do about the more important ones they voluntarily bring upon themselves.’
    • ‘It was a pause so infinitesimal that I almost didn't catch it, but I knew what I glimpsed.’
    minute, tiny, minuscule, extremely small, very small
    View synonyms


  • An indefinitely small quantity; a value approaching zero.

    • ‘These two concepts, infinitesimals and infinite quantities, however, were stirring great philosophical dilemmas.’
    • ‘Also in 1786 he again worked on his ideas for the differential and integral calculus, giving a new treatment of infinitesimals.’
    • ‘He began to study the geometry of infinitesimals and wrote to Oldenburg at the Royal Society in 1674.’
    • ‘Since his work made its appearance just before the dawn of calculus, infinitesimals will be used in the sequel.’
    • ‘The book shows how this notion can be used to form various kinds of infinities such as the projective plane, transfinite numbers, and infinitesimals.’


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