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 Empathy study shows ultilization and understanding of benefits remain a challenge, with about one-fourth of employees citing difficulty understanding benefits, accessing information, and navigating benefits complexity. —Sydney Lake, Fortune, 24 Feb. 2026

In less capable hands, these pieces could plod aimlessly and fade away, but Lawson knows how to wring complexity from a minimal set of elements. —Dash Lewis, Pitchfork, 24 Feb. 2026

Once back in the White House, the president acknowledged the complexity of the challenge. —David Brennan, ABC News, 24 Feb. 2026

Mrie’s memoir is a useful primer, if hardly the last word, on the complexities of the civil war and the shortcomings of the rebel forces. —Los Angeles Times, 24 Feb. 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