な adjective
でんとうてき
褌は、伝統的な日本の男性用下着です。
Fundoshi is traditional Japanese underwear for guys.
Transmits the feeling of wanting to unite behind something. What do people unite behind, if they're all part of a similar people? Tradition. Add 的 on there and you have traditional.
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.