complexity

complexity — noun

1. a state in which a thing has many connected pieces, making it hard to grasp, exp

1.nounC2
Definition

a state in which a thing has many connected pieces, making it hard to grasp, explain, or handle

Example

The complexity of the human brain continues to surprise neuroscientists every year.

uncountable: the complexity of [noun]

Aiko was surprised by the complexity of the visa application process.

Common collocations
  • sheer complexity
  • increasing complexity
  • level of complexity
  • complexity of the issue
Synonyms
  • intricacy

    focuses on fine detail and delicate connections rather than general difficulty

  • complication

    suggests something that makes a situation harder, often unexpectedly

Antonyms
  • simplicity

    the opposite quality of being easy to understand because there are few parts

Grammar Patterns

the complexity of + noun phrase

Usage Note

Uncountable noun. Frequently followed by 'of' plus a noun phrase that names the thing being described. Common in academic and technical writing.

Common Mistakes

The complexity of these problems are overwhelming.
The complexity of these problems is overwhelming.
complexity is uncountable, so the verb must be singular (is / was).
I was amazed by the complexities of the night sky.' (when referring to the general state)
I was amazed by the complexity of the night sky.
For the abstract quality, use the singular uncountable form.

2. the individual elements within a system or situation that create difficulty when

2.noun
Definition

the individual elements within a system or situation that create difficulty when trying to understand or deal with it

Example

The lawyer explained the legal complexities of signing the international trade deal.

plural noun: the complexities of [something]

Leila learned the complexities of managing a team across three different time zones.

Common collocations
  • hidden complexities
  • emotional complexities
  • political complexities
  • navigate the complexities
Synonyms
  • nuance

    emphasises small, subtle differences rather than overall difficulty

  • subtlety

    focuses on fine distinctions that are not obvious at first

Grammar Patterns

the complexities of + noun phrase

Usage Note

Almost always used in the plural form (complexities) when referring to specific difficult features. The singular form (a complexity) occurs but is less common and tends to refer to a single difficult aspect.

Common Mistakes

The complexity of the new rules confuse me.' (when referring to specific features)
The complexities of the new rules confuse me.
Use the plural when pointing to multiple difficult details.

Word family

  • complex
    adjectiveB2
  • complexion
    nounB2

Synonym discussion

Sense: noun/1

Intricacy highlights fine details that are closely connected and hard to separate — think of the intricacies of a watch mechanism. Complication suggests something that makes an already difficult situation worse, often unexpectedly, like a complication during surgery. Sophistication implies a high level of development or refinement that makes something complex, often in a positive or impressive way, such as the sophistication of modern software. Complexity is the broadest term: it covers any situation where many parts interact in ways that are hard to fully understand. For example, you might admire the intricacy of a lace pattern, worry about a complication in a legal case, appreciate the sophistication of a new phone, and study the complexity of climate change.

intricacycomplication ↗sophistication

Common collocations

Nouns

Adverbs

Phrases

  • the complexity of
  • a complexity to

Prepositions

Etymology

LatinFrenchEnglish

From Latin 'complexus' meaning 'braided together' (com- 'together' + plectere 'to weave'). Entered English via French 'complexité' in the 1600s, originally referring to something woven from many strands.