Other forms: complexes
Something complex is made of many connected parts and is not simple to understand. A complex system, a complex problem, unusually complex.
Complex and complicated overlap, but there is a useful difference: complex describes something with many interacting parts, and complicated describes something difficult. A complex machine may be easy to use. As a noun, a complex is a group of connected buildings — a sports complex — and in psychology it is a fixed pattern of feelings about something: an inferiority complex. Note complexity, the noun, and that the noun is stressed on the first syllable and the adjective often on the second.
1adjectivecomplexMade of many connected parts; not simple.
“The system is complex and almost nobody understands all of it.”
synonyms: complicated, intricate
2noungroupA group of connected buildings.
“The sports complex opened three years late.”
3nounfixedA fixed pattern of feelings about something.
“He has a complex about his accent that nobody else notices.”
Too few real examples of this word to estimate which sense is commonest.
complex is a quality of being intricate.
Also accepted in games: complicated
Latin complexus means embraced or woven together, from com-, together, plus plectere, to plait — the same root as plait and perplex. Something complex is literally braided, which is a better picture of the idea than complicated gives.
Proto-Indo-European
*pleḱ-
French
complexe
English, today
complex
Built from
Borrowed from French complexe. From French complexe, from Latin complexus, past participle of complector (“to entwine, encircle, compass, infold”), from com- (“together”) and plectō (“to weave, braid”). May be analyzed as com- + -plex. See complect. a doublet of complexus.
Etymology from Wiktionary, CC BY-SA