Complex

How to spell complex

7 letters · 2 syllables

How to pronounce complex

Say the part in capitals loudest.

What does complex mean?

1. adjectiveMade up of many connected parts and therefore difficult to understand or deal with.
2. nounA group of related buildings or facilities on one site.
3. nounA related group of repressed feelings or beliefs that influences a person's behaviour.

Complex in a sentence

• adjective

  The tax rules are too complex for most people to follow without help.

• noun

  The new sports complex includes a pool, a gym and several tennis courts.

• noun

  Years of criticism left him with a deep inferiority complex.

• adjective

  Engineers spent months untangling the complex wiring behind the panel.

• noun

  They moved into a quiet apartment complex near the river.

• noun

  The therapist suggested that her guilt complex stemmed from childhood.

Where does complex come from?

Language of origin: Latin

This word traces back to the Latin complexus, the past participle of complectere, which literally meant 'to embrace' or 'to weave together', formed from com- 'together' and plectere 'to plait or braid'. The underlying image is of separate strands twisted into one tangled whole, which is exactly why something complex feels intricate and hard to unpick. Latin passed it into English in the 1600s, at first as an adjective describing things composed of many connected parts, and only later as the noun for a cluster of buildings or, in psychology, a bundle of linked feelings. The same plectere root surfaces in relatives like 'perplex', 'plait' and 'complicate', all carrying that sense of folding and intertwining. The spelling stays close to the Latin, so the tricky part is simply remembering the silent-feeling -plex ending and the single internal 'm' rather than any doubling.

How the word is built

• com- (together)
• plex (from plectere: to weave, plait)