Learn how to say Complexes correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word complex:
consisting of two or more related parts
not simple; involved or complicated
a group of interrelated ideas, activities, etc. that form, or are viewed as forming, a single whole
an assemblage of units, as buildings or roadways, that together form a single, comprehensive group
an integration of impulses, ideas, and emotions related to a particular object, activity, etc., largely unconscious, but strongly influencing the individual’s attitudes and behavior
(popularly) an exaggerated dislike or fear