Meanings
plural imaginary numbers
- strict sensecomplex analysisA number of the form bi, where b is any real number and i denotes the imaginary unit.
If a#61;0, then x#61;ib is called an imaginary number. The message here is that we must introduce imaginary numbers in order to be able to solve quadratic equations in general.
2008, Donald A. McQuarrie, Mathematics for Physical Chemistry: Opening Doors, University Science Books, page 54Synonyms: purely imaginary number
- broadlycomplex analysisA number of the form a + bi, where a and b are real numbers and b is nonzero.
Synonyms & antonyms
nounA number of the form bi, where b is any real number and i denotes the imaginary unit.
More synonyms by meaning
noun(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
The adjective imaginary in this context was first used (as French imaginaire) by René Descartes in 1673, La Geometrie, referring to imaginary numbers in the broad sense, as non-real roots of polynomials. Descartes' usage was derogatory, but the concept later gained acceptance through the work of Leonhard Euler and Carl Friedrich Gauss in the 18th century.
Full word history & related roots →Translations
Bengali অবাস্তব সংখ্যা
- অবাস্তব সংখ্যা (obastob śoṅkha)number of the form bi
Bulgarian имагине́рно число́, компле́ксно число́
- имагине́рно число́ (imaginérno čisló)number of the form bi
- компле́ксно число́ (kompléksno čisló)number of the form a + bi, with b ≠ 0
Catalan nombre imaginari
- nombre imaginarinumber of the form bi
Chinese Cantonese 虛數 /虚数
- 虛數 /虚数 (heoi¹ sou³)number of the form bi
Chinese Mandarin 虛數 /虚数, 純虛數 /纯虚数
- 虛數 /虚数 (xūshù)number of the form bi
- 純虛數 /纯虚数 (chúnxūshù)number of the form bi
- 虛數 /虚数 (xūshù)number of the form a + bi, with b ≠ 0
Czech imaginární číslo
- imaginární číslonumber of the form bi
Danish imaginært tal
- imaginært talnumber of the form bi
Dutch imaginair getal
- imaginair getalnumber of the form bi
Esperanto imaginara nombro
- imaginara nombronumber of the form bi
Finnish imaginaariluku, imaginääriluku
- imaginaarilukunumber of the form bi
- imaginäärilukunumber of the form bi
- imaginaarilukunumber of the form a + bi, with b ≠ 0
- imaginäärilukunumber of the form a + bi, with b ≠ 0
French nombre imaginaire pur, nombre imaginaire
- nombre imaginaire purnumber of the form bi
- nombre imaginairenumber of the form a + bi, with b ≠ 0
German rein imaginäre Zahl, imaginäre Zahl
- rein imaginäre Zahlnumber of the form bi
- imaginäre Zahlnumber of the form bi
Greek φανταστικός αριθμός
- φανταστικός αριθμός (fantastikós arithmós)number of the form bi
Hebrew מספר מרוכב
- מספר מרוכבnumber of the form bi
Hungarian képzetes szám, imaginárius szám
- képzetes számnumber of the form bi
- imaginárius számnumber of the form bi
Icelandic þvertala
- þvertalanumber of the form bi
Japanese 虚数
- 虚数 (kyosū)number of the form bi
Korean 허수
- 허수 (heosu)number of the form bi
Latin quantitas imaginaria, numerus imaginarius
- quantitas imaginarianumber of the form bi
- numerus imaginariusnumber of the form bi
Latvian imaginārs skaitlis
- imaginārs skaitlisnumber of the form bi
Māori tau pohewa
- tau pohewanumber of the form bi
Persian عدد موهومی
- عدد موهومیnumber of the form bi
Polish liczba urojona, liczba zespolona
- liczba urojonanumber of the form bi
- liczba zespolonanumber of the form a + bi, with b ≠ 0
Portuguese número imaginário, número puramente imaginário
- número imaginárionumber of the form bi
- número puramente imaginárionumber of the form bi
Russian мни́мое число́
- мни́мое число́ (mnímoje čisló)number of the form bi
Spanish número imaginario
- número imaginarionumber of the form bi
Swedish imaginärt tal
- imaginärt talnumber of the form bi
Tagalog gunimbilang
- gunimbilangnumber of the form bi
Thai จำนวนจินตภาพ
- จำนวนจินตภาพ (jam-nuuan-jin-dtà-pâap)number of the form bi
Turkish sanal sayı
- sanal sayınumber of the form bi
Ukrainian уя́вне число́
- уя́вне число́ (ujávne čysló)number of the form bi
Vietnamese số ảo, số thuần ảo
- số ảonumber of the form bi
- số thuần ảonumber of the form bi
Cite this entry
imaginary number. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/imaginary%20number
“imaginary number.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/imaginary%20number. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “imaginary number,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/imaginary%20number.
Source: imaginary number on Wiktionary, CC BY-SA 4.0.