Use 'incoherence' when describing speech that is hard to understand due to lack of clear connections. The lecturer's incoherence left the students bewildered.
Pro Tip 2/3
Confused Thoughts
'Incoherence' can reflect disorganized thoughts, not just spoken or written words. His diary revealed a worrying level of incoherence.
Pro Tip 3/3
Abstract Ideas
Incoherence can also describe abstract concepts which are difficult to understand. They struggled with the incoherence of the philosophical text.