complex

(noun): A network of interconnected systems.
(noun): A collection of buildings with a common purpose, such as a university or military base.
(noun): An assemblage of related things; a collection.
(noun): An abnormal mental condition caused by repressed emotions.
(noun): (by extension) A vehement, often excessive psychological dislike or fear of a particular thing.
(noun): A structure consisting of a central atom or molecule weakly connected to surrounding atoms or molecules.
(noun): A complex number.
(verb): To form a complex with another substance
(verb): To complicate.
(adjective): Made up of multiple parts; composite; not simple.
(adjective): Not simple, easy, or straightforward; complicated.
(adjective): (of a number) Having the form a + bi, where a and b are real numbers and i is (by definition) the imaginary square root of −1.
(adjective): (of a function) Whose range is a subset of the complex numbers.
(adjective): Whose coefficients are complex numbers; defined over the field of complex numbers.
(adjective): A curve, polygon or other figure that crosses or intersects itself.