Antediluvian is an adjective and has two meanings:
1) of or belonging to the time before the Biblical flood
2) Ridiculously old fashioned or greatly out of date (sometimes used in a humorous sense)
Here, I'll use it in a sentence:
I often feel my mother wears clothes that are so antediluvian, she never has to worry about blending in with the crowds.
As soon as the latest iPhone came out, the older models became antediluvian to tech experts.
Hope this helped! :)
