enumeration
The careful act of listing or counting things in order.
Enumeration is the act of listing or counting things one by one, usually in a systematic way. When your teacher asks you to enumerate the reasons the American colonists wanted independence, she wants you to list them clearly: first, second, third. When a scientist enumerates the species living in a tide pool, she's carefully counting and recording each type of creature she finds.
It emphasizes being thorough and organized, making sure you don't skip anything important. Enumeration means being deliberate and complete, giving each item its own place in the list. The US Constitution uses enumeration when it lists the specific powers of Congress in Article I, carefully spelling out exactly what the legislative branch can and cannot do.
You might enumerate the steps in a science experiment, enumerate the items you need for a camping trip, or enumerate the complaints you have about your little brother's behavior (though that last list might get pretty long). The key is that you're being deliberate and complete, covering everything in order. When something involves enumeration, it means someone took the time to count or list everything carefully, one by one.