Complexness
Part of speech: noun
Definition: The state or quality of being complex.
Complexity
Part of speech: noun
Definition: The state of being complex; intricacy; entanglement.That which is and renders complex; intricacy; complication.
Example sentence: With genetic engineering, we will be able to increase the complexity of our DNA, and improve the human race. But it will be a slow process, because one will have to wait about 18 years to see the effect of changes to the genetic code.