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 diplomatic complexity of the question seemed to weigh on him. — Ruby Tandoh, New Yorker, 7 Sep. 2026

But for the users of AI models and services, it's created complexity and chaos as CEOs and IT managers spend an outsized amount of time and resources comparing costs and capabilities to avoid getting left behind. — Jonathan Vanian, CNBC, 6 Sep. 2026

Osteopathic medical education intentionally integrates biomedical, clinical, health systems and biomechanical sciences, and concepts aligned with complexity science into a coherent framework for physician formation. — Torie Bosch, STAT, 5 Sep. 2026

The doc covered similar ground, in many critics’ opinion offering greater sociological complexity than Primetime, which is more of a character study. — Nate Jones, Vulture, 5 Sep. 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