of ideas, thoughts, arguments, etc.) logical and well organized; easy to understand and clear (Oxford)
If someone is coherent, you can understand what that person says (Cambridge)
She only became coherent again two hours after the attack. (Oxford)
You're not being very coherent . (Oxford)
When she calmed down, she was more coherent . (Cambridge)
became coherent
being very coherent
more coherent
Consistent
Meaningful
Irrational
Unreasonable
Coherently
Coherence