complex

1. An assemblage of related things; a collection.Examples: "Since then, a good deal of research has documented and concluded that the nominal species A. fraterculus actually comprises an unresolved complex of cryptic species."Synonyms: species complex, species group, species aggregate

2. (psychology) A group of emotionally charged ideas or mental factors, unconsciously associated by the individual with a particular subject, arising from repressed instincts, fears, or desires and often resulting in mental abnormality.Examples: "Jim has a real complex about working for a woman boss."Synonyms: constellation

3. (psychology) A group of emotionally charged ideas or mental factors, unconsciously associated by the individual with a particular subject, arising from repressed instincts, fears, or desires and often resulting in mental abnormality.Synonyms: constellation

4. (chemistry) A structure consisting of a central atom or molecule weakly connected to surrounding atoms or molecules, as for example coordination complexes in inorganic chemistry and protein complexes in biochemistry.Examples: "Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis:[…]. The evolutionary precursor of photosynthesis is still under debate, and a new study sheds light. The critical component of the photosynthetic system is the “water-oxidizing complex”, made up of manganese atoms and a calcium atom."

5. (mathematics) A complex number.Examples: "The interesting aspect here is that U₃ is irreducible, even though all irreps over the complexes are one-dimensional because ℤ₄ is abelian."

6. (linguistics) A multimorphemic word, one with several parts, one with affixes.

1. (chemistry, intransitive) To form a complex with another substance.intransitive

2. (transitive) To complicate.transitive