complex (complexity): in general, consisting of several parts. This term has several specific uses, depending on the type of element that it describes.

complex [1]: A complex sound is one that requires the articulators to move during its pronunciation, essentially consisting of a combination of two or more simpler sounds. Diphthongs are complex vowels; labialized and palatalized consonants and affricates are three kinds of complex consonants. [Spanish: complejo [1]]

complex [2]: A complex stem is a polymorphemic stem (one that consists of more than one morpheme), especially a derived stem. Contrast root; compare compound. [Spanish: complejo [2]]

complex [3]: A complex clause is a clause which contains one or more other clauses. [Spanish: complejo [3]]