Turns up after the deadline around mid-evening armed ultimately to the teeth, as the description goes (6)
I believe the answer is:
dental
If this is the answer, I'm afraid I cannot explain it.
Can you help me to learn more?
(Other definitions for dental that I've seen before include "sort of surgeon" , "Concerning teeth" , "concerned with choppers" , "Relating to teeth" , "Concerned with teeth" .)