Definition of complexnext
1
as in facility
a structure that is designed and built for a particular purpose an apartment complex

Synonyms & Similar Words

2
as in system
something made up of many interdependent or related parts a complex of government programs designed to assist the needy

Synonyms & Similar Words

Synonym Chooser

How does the adjective complex differ from other similar words?

Some common synonyms of complex are complicated, intricate, involved, and knotty. While all these words mean "having confusingly interrelated parts," complex suggests the unavoidable result of a necessary combining and does not imply a fault or failure.

a complex recipe

When is complicated a more appropriate choice than complex?

While the synonyms complicated and complex are close in meaning, complicated applies to what offers great difficulty in understanding, solving, or explaining.

complicated legal procedures

When might intricate be a better fit than complex?

The synonyms intricate and complex are sometimes interchangeable, but intricate suggests such interlacing of parts as to make it nearly impossible to follow or grasp them separately.

an intricate web of deceit

When is it sensible to use involved instead of complex?

Although the words involved and complex have much in common, involved implies extreme complication and often disorder.

a rambling, involved explanation

When would knotty be a good substitute for complex?

While in some cases nearly identical to complex, knotty suggests complication and entanglement that make solution or understanding improbable.

knotty ethical questions

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of complex
Adjective
But the alderman has also repeated his criticism of the firm’s complex connection to ICE, even after Wyper’s June comments. Jake Sheridan, Chicago Tribune, 17 July 2026 Lest things get predictable, Tasjan’s adept at letting the music battle with the lyrics in a way that hints at how any experience is far more complex than we are led to believe. Marissa R. Moss, Rolling Stone, 17 July 2026
Noun
The tragic shooting involved a Georgia family and took place at an apartment complex in Kissimmee on Sunday, July 12, Osceola County Sheriff Chris Blackmon said during a Monday news conference. Natalie Neysa Alund, USA Today, 16 July 2026 One of the complex’s existing stages is being converted to accomodate LED volume technology and real-time digital environments using advanced camera tracking, and real-time 3D engines such as Unreal Engine. Nellie Andreeva, Deadline, 16 July 2026 See All Example Sentences for complex
Recent Examples of Synonyms for complex
Adjective
  • An official also noted at a briefing last week that testing has taken longer because the genome of cyclospora is more complicated than that of other parasites.
    Blake Ellis, CNN Money, 20 July 2026
  • As anyone who has searched for the perfect white T-shirt knows, finding wardrobe basics can prove surprisingly complicated.
    Sophie Wirt, InStyle, 19 July 2026
Adjective
  • Fabricating a purely electromechanical robot at the millimeter scale requires intricate, heavy motors that consume significant power, typically draining tiny batteries within mere minutes of operation.
    New Atlas, New Atlas, 18 July 2026
  • With denim as its core fabric, the collection incorporated intricate plissé work, feather and floral constructions and delicate lace applications.
    Angela Velasquez, Footwear News, 17 July 2026
Noun
  • Other military facilities were also hit, according to CENTCOM.
    Jomana Karadsheh, CNN Money, 19 July 2026
  • Under the program, TOTE Services will act as vessel construction manager, while Hanwha Philly Shipyard will construct the ships at its Philadelphia facility.
    Atharva Gosavi, Interesting Engineering, 18 July 2026
Noun
  • Jones said an increase in transfers between river systems would normally not affect the downstream communities, but potentially could in a drought.
    Zaire Breedlove, Charlotte Observer, 22 July 2026
  • In domains where lives, safety, or significant financial outcomes are at stake, organizations need AI systems trained, validated, and measured specifically for those environments.
    TerDawn DeBoe, Forbes.com, 22 July 2026
Verb
  • The legal standard to charge law enforcement for a shooting that occurs while on duty is high, which also complicates calls for accountability.
    Nicki Brown, CNN Money, 18 July 2026
  • That uniformity stripped away many of the confounding lifestyle differences that complicate other epidemiological studies.
    Samantha Agate, Sacbee.com, 18 July 2026
Adjective
  • Nike’s most sophisticated cushioning to date will get you outside and hitting PRs in no time, also functioning at its prime from the gym to the errand run.
    Stacia Datskovska, Footwear News, 20 July 2026
  • From classic penny loafers to trendy ruched iterations, these shoes make a versatile and sophisticated alternative to other flats, easily elevating any outfit formula.
    India Roby, Glamour, 20 July 2026
Adjective
  • Do not undergo or pay for any treatment before reading detailed documentation of the procedure.
    Ella Moore July 23, Miami Herald, 23 July 2026
  • Razer Viper Gaming Mouse Deal Weighing just 55 grams, the Razer Viper V3 Pro transitions effortlessly from detailed design projects and study sessions to competitive after-class gaming.
    Juhi Wadia, PC Magazine, 22 July 2026
Noun
  • If no deal is made, people with the aforementioned health insurance plans through United will no longer be able to get in-network care with UHealth doctors and other providers across UHealth’s South Florida facilities.
    Michelle Marchante July 22, Miami Herald, 22 July 2026
  • Emery believed Rashford at his best was one of the most threatening attackers in the world and backed himself and his support network to rejuvenate the player.
    Chris Weatherspoon, New York Times, 22 July 2026

Browse Nearby Words

Cite this Entry

“Complex.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/complex. Accessed 23 Jul. 2026.

More from Merriam-Webster on complex

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster