To confuse, mix up (something) with something else.
To make unnecessarily complex.
To fold or coil into numerous overlapping layers.
Convoluted.
Coiled such that one edge is inside, and one outside the coil, giving a spiral effect in cross section.
To change the meaning of (something) in a deceptive or misleading way.
To make (something) more sophisticated (“complex, developed, or refined”); to develop, to refine.
To make (oneself or someone) more sophisticated (“experienced in the ways of the world, that is, cosmopolitan or worldly-wise”); to cosmopolitanize.
To make (something) less innocent or natural; to artificialize.
To alter and make impure (something) by mixing it with some foreign or inferior substance, especially with an intention to deceive; to adulterate; (generally) to corrupt or deceive (someone, their thinking, etc.).
To practise sophistry (“the (deliberate) making of arguments that seem plausible but are fallacious or misleading”).
A person who is sophisticated (“experienced in the ways of the world, that is, cosmopolitan or worldly-wise”), or who has sophisticated tastes.
Of a person: experienced in the ways of the world; cosmopolitan, worldly-wise.
Of art or other things: appealing to the tastes of an intellectual or sophisticated (sense 1.1) person; cerebral; also, cultured, elegant, refined.