adverb, noun, の adjective
If you come to the party wearing something really, really old, everyone will know you're from ancient times (as if your wrinkles didn't give it away already, right?).
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
The kappa is an ancient Japanese yokai.
In ancient times, this pond was known as "WaniKani Pond."
The toilet is a wonderful invention that has been handed down since ancient times to the present-day.