Consisting of many different and connected parts that make something difficult to understand.

“The rules of the game are quite complex, so it takes a while to learn them.”

A group of similar buildings or facilities located on the same site.

“She lives in a large apartment complex with its own gym and pool.”

A core of related concerns or feelings that cause emotional or mental conflict.

“He's always felt like he wasn't good enough, giving him a bit of an inferiority complex.”