📒 made of many different things or parts that are connected; difficult to understand
a complex problem/issue/process/system
a complex argument/subject
complex machinery
📒 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)
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.