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

The World Cup offers us a fascinating glimpse at the complexities of national pride and identity. — Aj Willingham, AJC.com, 6 July 2026

Short of a revolution in complexity theory, a comprehensive result is out of the question. — Ben Brubaker, Quanta Magazine, 6 July 2026

The musical’s overture gives you a sense of the complexity that’s needed to make seeming simple and straightforward material really soar. — Christopher Arnott, Hartford Courant, 6 July 2026

Depending on the complexity of the case, fees generally start at $2,500 and can go to $5,000 or more. — Nick Perry, USA Today, 6 July 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