First Class
First Rank, The Best
noun, の adjective
When you're equal to one you are the very top. You are first class and first rank. In fact, you are the best.
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. いち gets shortened to いっ though, so watch out for that if you want to remain the best, yeah?
この宝くじの一等の賞金はいくらですか？
How much is the first prize for this lottery?
このベーコンのキーホルダーは、私がベーコンのコスプレ大会で一等賞を取った時にもらったんです。
I won this bacon keychain when I won first prize in the bacon costume competition.
一等車に乗ってるとは、さすがコウイチだね。
You are in the first-class carriage, yeah? That's so like you, Koichi!