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com·plex (kəm-plĕks, kŏmplĕks)
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adj.
1.
a. Consisting of interconnected or interwoven parts; composite: complex equipment with multiple components.
b. Composed of two or more units: a complex carbohydrate.
2. Difficult to understand for being intricate or involved; complicated: a complex problem.
3. Grammar
a. Consisting of at least one bound form. Used of a word.
b. Consisting of an independent clause and at least one other independent or dependent clause. Used of a sentence.
n. (kŏmplĕks)
1. A whole composed of interconnected or interwoven parts: a complex of cities and suburbs; the military-industrial complex.
2. A building or group of buildings used for a single purpose: a sports complex.
3. In psychoanalysis, a group of related, often repressed ideas and impulses that compel characteristic or habitual patterns of thought, feelings, and behavior.
4. An exaggerated or obsessive concern or fear: has a complex about his weight.
5. Medicine The combination of factors, symptoms, or signs of a disease or disorder that forms a syndrome.

[Latin complexus, past participle of complectī, to entwine; see COMPLECT.]

com·plexly adv.
com·plexness n.

Synonyms: complex, complicated, intricate, involved, tangled
These adjectives mean having parts so interconnected as to hamper comprehension or perception of the whole. Complex implies a combination of many interwoven parts: The composer transformed a simple folk tune into a complex set of variations. Complicated stresses a relationship of parts that affect each other in elaborate, often obscure ways: The party's complicated platform confused many voters. Intricate refers to a pattern of intertwining parts that is difficult to follow or analyze: "No one could soar into a more intricate labyrinth of refined phraseology" (Anthony Trollope).
Involved implies a close but confusing interconnection between many different parts: The movie's plot was criticized as being too involved. Tangled strongly suggests the random twisting of many parts: "Oh, what a tangled web we weave, / When first we practice to deceive!" (Sir Walter Scott).

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
 

Indo-European & Semitic Roots Appendices

    Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

    Indo-European Roots

    Semitic Roots

    The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.