complex
com·plex/kɑmˈplɛks/adjective, noun, verb
complex is spelled C-O-M-P-L-E-X, 2 syllables: com·plex. The wrong spelling people search most is comlex: about 240 Bing searches a month in the United States (September 2025 to August 2026), about 1 in 27 of all searches for the word. Complex is an adjective meaning “Made up of multiple parts; composite; not simple”.
How many letters and syllables are in complex?
| Letters | 7: C-O-M-P-L-E-X |
|---|---|
| Syllables | 2: com·plex |
| In writing | 72 times per million words; the 1,457th most frequent word form |
| Wrong spellings searched | 1; the most searched, comlex, about 240 Bing searches a month (all of them) |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); Bing searches in the United States: the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026); rhymes and same-letter words are computed by PlainSpell from its own word list.
How do you spell complex?
Complex is spelled C-O-M-P-L-E-X. One wrong spelling is searched or written often enough to measure; together they are about 1 in 27 of the searches for complex in either form.
Bing searches in the United States: the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026). Wrong spellings are taken from Wiktionary entries tagged "misspelling" and its obsolete or nonstandard forms, Wikipedia's Lists of common misspellings and the codespell dictionary, then measured. The proofreader's marks show the change that corrects each one.
How common is complex?
Complex appears 72 times per million words in written English, the 1,457th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce complex?
- UK /ˈkɒmplɛks/
- UK /kəmˈplɛks/
- US /kɑmˈplɛks/
As a noun (“A network of interconnected systems”): /ˈkɒmplɛks/, /ˈkɑmˌplɛks/.
Complex has 2 syllables, split com·plex in writing.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-uk-complex.ogg, En-us-complex-adj.ogg, En-us-complex-noun.ogg, Wikimedia Commons (author and licence on each file's page).
What rhymes with complex?
3 words on PlainSpell end in the same sounds as complex from its last stressed vowel (/ɛks/):
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of complex
- more complex comparative
- most complex superlative
- complexes plural, present, singular, he/she/it
- complexing participle, present
- complexed participle, past
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does complex mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
Made up of multiple parts; composite; not simple.
a complex being; a complex idea
- 2
Not simple, easy, or straightforward; complicated.
- 3
Having the form a + bi, where a and b are real numbers and i is (by definition) the imaginary square root of −1.
complex number
- 4
Whose range is a subset of the complex numbers.
complex function
- 5
Whose coefficients are complex numbers; defined over the field of complex numbers.
complex polynomial
- 6
A curve, polygon or other figure that crosses or intersects itself.
noun
- 1
A network of interconnected systems.
military–industrial complex
- 2
A collection of buildings with a common purpose, such as a university or military base.
- 3
An assemblage of related things; a collection.
- 4
An organized cluster of thunderstorms.
- 5
A cluster of wildfires burning in the same vicinity.
The fire complex began as two separate fires.
- 6
A group of closely related species, often distinguished only with difficulty by traditional morphological methods.
- 7
A group of emotionally charged ideas or mental factors, unconsciously associated by the individual with a particular subject, arising from repressed instincts, fears, or desires and often resulting in mental abnormality.
Jim has a real complex about working for a woman boss.
- 8
A fixed mental tendency or obsession.
verb
- 1
To form a complex with another substance.
- 2
To complicate.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Complex in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| French | complexe |
| German | kompliziert , komplex , Komplex , Gewitterkomplex |
| Portuguese | complexo , complicado , composto |
| Spanish | complejo, complexo , complejizar |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does complex come from?
From French complexe, from Latin complexus, past participle of complector (“to entwine, encircle, compass, infold”), from com- (“together”) and plectō (“to weave, braid”). May be analyzed as com- + -plex. See complect. Doublet of complexus.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).