I’m sure I’ve come across this word in other readings or at least once when I was in school, but I could not remember what it meant. I found it while reading Speaking in Bones. I had to look it up.
Antediluvian – of or belonging to the time before the Biblical Flood; ridiculously old-fashioned
Usage: “I still keep hard copy on all my cases. Antediluvian, but there you have it.”