infinitesimal

See also: infinitésimal

English

Etymology

From New Latin īnfīnītēsimus +‎ -al. Displaced earlier coordinate term fluxion.

Pronunciation

• IPA^(key): /ˌɪnfɪnɪˈtɛsɪməl/

• Audio (US):

  (file)

• Rhymes: -ɛsɪməl

Adjective

infinitesimal (comparative more infinitesimal, superlative most infinitesimal)

1. Incalculably, exceedingly, or immeasurably minute; vanishingly small.

   Do you ever get the feeling that you are but an infinitesimal speck, swallowed by the vastness of the universe and beyond?

   • 1913, Arthur Conan Doyle, “(please specify the page)”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton, →OCLC:

     "You will conceive a bunch of grapes," said he, "which are covered by some infinitesimal but noxious bacillus."

   • 2001, Eoin Colfer, Artemis Fowl, page 221:

     Then you could say that the doorway exploded. But the particular verb doesn't do the action justice. Rather, it shattered into infinitesimal pieces.

2. (mathematics, not comparable) Of or pertaining to non-zero quantities whose magnitude is less than any positive rational number.
3. (informal) Very small.

Synonyms

• See also Thesaurus:tiny

Antonyms

• infinite
• enormous

Derived terms

• infinitesimal analysis
• infinitesimalness
• noninfinitesimal

Translations

very small

• Bulgarian: безкрайно малък (bezkrajno malăk)
• Czech: nepatrný (cs)
• Dutch: (jargon) infinitesimaal (nl), (colloquial) oneindig klein
• Finnish: äärettömän pieni, infinitesimaalinen
• French: infinitésimal
• Greek: απειροελάχιστος (el) m (apeiroeláchistos)
• Hebrew: אַפְסִי m (afsí)
• Māori: merowhetau
• Polish: nieskończenie mały, infinitezymalny (pl)
• Russian: бесконе́чно ма́лый (beskonéčno mályj)
• Serbo-Croatian: инфинитезималан
• Spanish: infinitésimo
• Tagalog: napakalinggit

mathematics: pertaining to values that approach zero

• Bulgarian: клонящ към нула (klonjašt kăm nula)
• Czech: infinitezimální (cs)
• Finnish: infinitesimaalinen
• Greek: απειροστός (el) m (apeirostós)
• Polish: nieskończenie mały, infinitezymalny (pl)
• Spanish: infinitesimal (es)
• Tagalog: napakalinggit

Noun

infinitesimal (plural infinitesimals)

1. (mathematics) A non-zero quantity whose magnitude is smaller than any positive number (by definition it is not a real number).

   Antonym: infinity

2. Something infinitesimally small.
   • 1934, Ernest Bramah [pseudonym; Ernest Brammah Smith], The Bravo of London:

     It occurred to the hearer, who was accustomed to glean much of his knowledge from the infinitesimals of tone, that there was a spice of "It is my duty and I will" in this praiseworthy resolve which fell short of the ecstatic resolution of the Saturday Nora.

Derived terms

• infinitesimal calculus
• infinitesimally

Translations

A non-zero quantity whose magnitude is smaller than any positive number

• Bulgarian: безкрайно малка величина f (bezkrajno malka veličina)
• Finnish: infinitesimaali
• French: infinitésimal (fr)
• Greek: πολλοστημόριο (el) n (pollostimório)
• Hungarian: infinitezimális (hu)
• Macedonian: инфинитезимала f (infinitezimala), бесконечно мала величина f (beskonečno mala veličina)
• Macedonian: инфинитезимала f (infinitezimala)
• Polish: wielkość nieskończenie mała f
• Russian: бесконе́чно малая величина́ f (beskonéčno malaja veličiná)
• Swedish: infinitesimal (sv)
• Tagalog: napakalinggit

Spanish

Pronunciation

• IPA^(key): /infinitesiˈmal/ [ĩɱ.fi.ni.t̪e.siˈmal]
• Rhymes: -al
• Syllabification: in‧fi‧ni‧te‧si‧mal

Adjective

infinitesimal m or f (masculine and feminine plural infinitesimales)

1. infinitesimal

Derived terms

• cálculo infinitesimal m (“infinitesimal calculus”)
• infinitesimalmente

Further reading

• “infinitesimal”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025