complex / complexity
If something is complex, it is not simple and that means it can be hard to understand. In other words, it has many parts and normally takes a long time to study or understand. It can be used in a neutral way, but is sometimes negative, when a person wants to say something should be simple, but isn’t. Very often the structures, models and theories that you come across at university are complex – this often means that you need to analyse them – in other words, break them down into the different components. The noun form is ‘complexity’.
This is a complex question which requires careful consideration.
The complexity of the problem meant that we needed to spend many more hours on identifying its causes and recommending solutions.