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Definitions

complex

[kuhm-pleks, kom-pleks, kom-pleks] / kəmˈplɛks, ˈkɒm plɛks, ˈkɒm plɛks /
ADJECTIVE
involved, intricate
Synonyms
STRONGEST
complicated convoluted
STRONG
composite compound conglomerate manifold mosaic motley multiple multiplex
WEAK
circuitous compounded confused elaborate entangled heterogeneous knotty labyrinthine mingled miscellaneous mixed mixed-up multifarious multiform tangled tortuous variegated
Antonyms
STRONGEST
simple
STRONG
single uniform unmixed
WEAK
apparent clear direct discernible easy evident homogeneous obvious plain
ADJECTIVE
difficult to understand
Synonyms
STRONGEST
complicated convoluted disturbing intricate obscure perplexing sophisticated
STRONG
byzantine winding
WEAK
Daedalean Gordian abstruse bewildering circuitous confused crabbed cryptic discursive disordered enigmatic entangled excursive hidden impenetrable inscrutable interwoven involved jumbled knotted knotty labyrinthine mazy meandering mingled mixed muddled paradoxical puzzling rambling recondite round-about sinuous snarled tangled tortuous undecipherable unfathomable
Antonyms
STRONGEST
easy simple
WEAK
apparent clear direct discernible evident homogeneous obvious plain uniform
NOUN
composite, aggregate
Synonyms
STRONGEST
compound network structure system
STRONG
association conglomerate ecosystem entanglement group organization scheme syndrome synthesis totality
Antonyms
STRONG
division separation
NOUN
psychological problem
Synonyms
STRONG
anxiety fear fixation hang-up insanity mania neurosis obsession phobia preoccupation repression
WEAK
a thing about something exaggerated reaction fixed idea idée fixe
Antonyms
STRONG
balance sanity

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“We recognize this has been a complex and, at times, difficult situation for members of our campus community.”

From Los Angeles Times • Apr. 10, 2026

Perhaps you’re looking for basic financial planning — help with tasks such as retirement planning, tax planning and budgeting — but aren’t interested in alternative investments or complex portfolio-construction strategies.

From MarketWatch • Apr. 10, 2026

They rely on golfers to self-enforce a complex book of rules.

From The Wall Street Journal • Apr. 10, 2026

Plants have also suspended or reduced production in the UAE, Saudi Arabia, Iran, Jordan and Qatar, whose Qafco complex accounted for 14 percent of global trade in urea.

From Barron's • Apr. 10, 2026

She’s a widow who lives in the senior citizen apartment complex a quick bike ride away from our house.

From "Shine!" by J.J. and Chris Grabenstein

Vocabulary lists containing complex

Academic Vocabulary: Core Tier 2 Words, List 2

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

The Catcher in the Rye

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Vocabulary from "Stop Expecting Games to Build Empathy" by Julie Muncy

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!