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 wall labels at the Jewish Museum can only hold so much complexity, but that doesn’t stop the objects. — Emily Watlington, ARTnews.com, 24 Aug. 2026

Summary The finalists for the Ocean Photographer of the Year 2026 have been announced, showcasing the our sea's complexity, beauty, and urgent need for protection. — Cecilia Rodriguez, Forbes.com, 23 Aug. 2026

That complexity reveals itself on the field, where some rosters can reach 105 players between offense, defense and special teams. — Ira Gorawara, New York Times, 23 Aug. 2026

Emerging direct lithium extraction technologies are still struggling with downstream concentration costs, high energy consumption, and scale-up complexity. — Maria Mocerino, Interesting Engineering, 22 Aug. 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