Complex Main Adjective ˈkɒmpleks Kəmˈpleks Problem/Issue/Process/System Argument/Subject Machinery

• a complex problem/issue/process/system
• a complex argument/subject
• complex machinery
• the complex structure of the human brain

complex

1. made of many different things or parts that are connected; difficult to understand
• SYNONYM complicated
  https://www.oxfordlearnersdictionaries.com/definition/english/complicated
• a complex problem/issue/process/system
• a complex argument/subject
• complex machinery
• the complex structure of the human brain
• Scientists need a better understanding of the complex interactrions that cause hurricanes to intensify.
• We live in an increasingly complex world.
• a highly complex situation

Extra Examples

• technically complex surgery
• She managed to put over a fairly complex argument in a brilliantly simple way.
• The mechanism involves a complex arrangement of rods and cogs.
• How does the press explore thecomplex relationship between the two countries?
2. containing one main part (= the root of a word or main clause of a sentence) and one or more other parts (called affixes or subordinate clauses)
• COMPARE compound
  https://www.oxfordlearnersdictionaries.com/definition/english/compound_3
• In the complex sentence, ‘I'd like to go to the beach, if it's warm enough’, ‘I'd like to go to the beach’ is the main clause, and ‘if it's warm enough’ is the subordinate clause.

Word Origin

• mid 17th cent. (in the sense ‘group of related elements’): from Latin complexus, past participle (used as a noun) of complectere ‘embrace, comprise’, later associated with complexus ‘plaited’; the adjective is partly via French complexe.