Word
imaginary
Phoneticsimag·i·nary
US/ˌɪˈmædʒəˌnɛɹi/
UK/ɪmˈædʒɪnəɹi/
Definitions
01not real
B1 · Intermediate
adj. existing only in your mind or in a story, not in the real world.
adj. existing only in the imagination; lacking a basis in physical reality.
日本語:架空※
“As a child, she had an imaginary friend who went everywhere with her.”
“The novelist created an imaginary kingdom with its own complex history and unique language to serve as the setting for the series.”
Pitfall
He has an imaginative friend.
He has an imaginary friend.
Use 'imaginary' for things that aren't real. Use 'imaginative' to describe a person who has a good imagination.
02mathematical numbers
C1 · Advanced Mathematics Technical
adj. used to describe a type of number in math that is a multiple of the square root of minus one.
adj. relating to the part of a complex number that is a multiple of the imaginary unit (the square root of -1).
“In this equation, 'i' represents an imaginary number.”
“The student struggled to visualize how imaginary numbers could be plotted on a complex plane alongside real numbers.”
Usage
Usually placed before the noun 'number' or 'unit'.
Antonyms
03social shared ideas
C2 · Proficiency Countable noun Academic
n. the collection of ideas, symbols, and stories that a group of people share to understand their society.
n. the set of values, symbols, and institutions common to a social group through which they imagine their social whole.
“The book explores the national imaginary of 19th-century France.”
“Scholars often discuss the 'social imaginary' to explain how modern citizens perceive their connection to millions of strangers within the same state.”
Teaching tip
This is a highly specialized term in sociology and philosophy; learners will rarely encounter it in everyday conversation.
Synonyms
Collocations
Common phrases and expressions where native English speakers use the word “imaginary” in context.
Verb
01. create an imaginary world
“The author spent years creating an imaginary world for her fantasy series.”
verb + adj + noun
02. fear an imaginary danger
“There is no need to worry; you are simply fearing an imaginary danger.”
verb + adj + noun
Adjective
03. imaginary friend
“When he was five years old, he used to play in the garden with his imaginary friend.”
adj + noun
04. imaginary number
“In our advanced math class, we learned how to calculate the square root of an imaginary number.”
adj + noun
05. imaginary world
“Children often create an imaginary world where they can be whoever they want.”
adj + noun
06. purely imaginary
“The characters in this novel are purely imaginary and do not represent real people.”
adv + adj
Etymology
From Middle English ymaginarie, ymagynary, from Latin imāginārius (“relating to images, fancied”), from imāgō, equivalent to imagine + -ary. The mathematical sense derives from René Descartes's use (of the French imaginaire) in 1637, La Geometrie, to ridicule the notion of regarding non-real roots of polynomials as numbers. Although Descartes' usage was derogatory, the designation stuck even after the concept gained acceptance in the 18th century.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Domains
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B1 PreliminaryIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.4.0–5.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 3.0–3.544–71TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.550–784
- Frequency
- Frequent
- Level
- B1 · IntermediateOxford
- Updated
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QR code
englishreference.com/q/imaginary
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「日本語」 data: JMdict (EDRDG), CC BY-SA 4.0