# complex

> English word · Adjective · IPA /ˈkɒmplɛks/ · frequency rank #1,449

## Definitions
1. Made up of multiple parts; composite; not simple.
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.
4. Whose range is a subset of the complex numbers.
5. Whose coefficients are complex numbers; defined over the field of complex numbers.
6. A curve, polygon or other figure that crosses or intersects itself.

## Etymology
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.

## Easily confused with
- **couple** (https://plainspell.com/en/vs/complex-vs-couple)
- **comply** (https://plainspell.com/en/vs/complex-vs-comply)
- **Copley** (https://plainspell.com/en/vs/complex-vs-copley)
- **couples** (https://plainspell.com/en/vs/complex-vs-couples)
- **coupled** (https://plainspell.com/en/vs/complex-vs-coupled)
- **coupler** (https://plainspell.com/en/vs/complex-vs-coupler)
- **complied** (https://plainspell.com/en/vs/complex-vs-complied)
- **complies** (https://plainspell.com/en/vs/complex-vs-complies)
- **compel** (https://plainspell.com/en/vs/compel-vs-complex)
- **compile** (https://plainspell.com/en/vs/compile-vs-complex)
- **complete** (https://plainspell.com/en/vs/complete-vs-complex)
- **compiler** (https://plainspell.com/en/vs/compiler-vs-complex)

## Common misspellings (11)
`ccomplex`, `cmoplex`, `comlpex`, `commplex`, `compelx`, `complexx`, `compllex`, `complxe`, `compplex`, `copmlex`, `ocmplex`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/complex