adjective

1. consisting of two or more related parts
2. not simple; involved or complicated

Etymology: < L complexus, pp. of complecti, to encircle, embrace < com-, with + plectere, to weave: see flax

noun

1. a group of interrelated ideas, activities, etc. that form, or are viewed as forming, a single whole
2. an assemblage of units, as buildings or roadways, that together form a single, comprehensive group
3. Psychoanalysis
   1. 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
   2. popularly an exaggerated dislike or fear