ENGLISH
REFERENCE

complex

adj. · n. · v.
US //ˈkɑmpɫɛks// com·plex
  1. 1 complicated (adj.)
    B1 Intermediate

    having many different parts and being difficult to understand.

    consisting of many interconnected parts; intricate or complicated in structure.

    Example

    The instructions for the new software were too complex for me to follow.

    Example

    The legal team spent months untangling the complex web of financial transactions that led to the company's collapse.
  2. 2 mathematical numbers (adj.)
    C1 Advanced Technical Math

    related to a type of number that has both a real part and an imaginary part.

    pertaining to numbers of the form a + bi, where i is the square root of negative one.

    Example

    We learned how to plot complex numbers on a graph today.

    Example

    The engineer used complex variables to model the fluid dynamics of the turbine blades under high pressure.
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  1. 3 group of buildings (n.)
    B2 Upper Intermediate

    a group of buildings or rooms that are close together and used for a similar purpose.

    a whole structure or connected series of buildings or facilities.

    Example

    The new sports complex has a swimming pool and three gyms.

    Example

    The industrial complex on the edge of the city houses several manufacturing plants and a central distribution warehouse.
  2. 4 psychological issue (n.)
    B2 Upper Intermediate Psychology

    a group of feelings or worries that influence how someone behaves, often without them knowing it.

    a related group of repressed mental networks that dominate a person's emotional life.

    Example

    He has a bit of a superiority complex and always thinks he is right.

    Example

    Psychologists suggest that her childhood experiences contributed to an inferiority complex that manifests in her professional life.
  3. 5 chemical structure (n.)
    C1 Advanced Technical Science

    a structure where a central atom is connected to other molecules.

    a molecular entity formed by the loose association of two or more component molecules or ions.

    Example

    The scientist studied how the protein complex reacts to the new medicine.

    Example

    The stability of the metal-ligand complex is highly dependent on the pH levels of the surrounding solution.
  4. 6 to join together (v.)
    C2 Proficiency Technical Science

    to join with another substance to form a single structure.

    to form a complex with another substance; often used in biochemical contexts.

    Example

    The dye will complex with the fibers to create a permanent color.

    Example

    The researchers observed the metal ions as they began to complex with the organic molecules in the sample.
    • dissociate
Origin

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. Doublet of complexus.

Word family

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