Japan's deepest subway line is the Oedo line, which goes as low as 48 meters below ground.
Jealousy is the deepest sin of human sins.
Salmon and I had our wedding ceremony in a romantic hidden cave located at the deepest part of the ocean that light can still reach.
The most deep is the deepest.
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.