complexity

noun

com·​plex·​i·​ty kəm-ˈplek-sə-tē 

käm-

plural complexities

1

: something complex

the complexities of the murder trial

2

: the quality or state of being complex

the complexity of the contract

Synonyms of complexity

• complexness
• sophistication
• intricacy
• elaborateness

Examples of complexity in a Sentence

He was impressed by the complexity of the music.

The diagram illustrates the complexity of the cell's structure.

He doesn't grasp the complexity of the situation.

Recent Examples on the Web

For each gene, the catalogue would ideally include its technical complexity, which methods can reliably analyze it, and document when a specialized test is required. — Euan Ashley, STAT, 1 Oct. 2026

The conversation and the word itself, which gives the seventh and final episode its title, unlocks the Biblical underpinnings and the complexities governing many of the main characters. — Daniel Fienberg, HollywoodReporter, 1 Oct. 2026

The challenge of breaking down complex policy problems into simple, indicative binary choices hints at the complexities inherent to Hanson’s model. — Simon Denny, Artforum, 1 Oct. 2026

As the company grows, more people, more complexity, more decisions, that same model becomes a bottleneck. — Monte Wyatt, Forbes.com, 1 Oct. 2026

Word History

Etymology

complex entry 2 + -ity, perhaps after French complexité

First Known Use

1661, in the meaning defined at sense 1

Rhymes for complexity

• convexity
• perplexity

Kids Definition

complexity

noun

com·​plex·​i·​ty kəm-ˈplek-sət-ē 

käm-

plural complexities

1

: something complex

the complexities of the English language

2

: the quality or state of being complex