Aiueo Order
Syllabary Order
noun
This is a little confusing for someone who didn't grow up with the Japanese language. You have fifty sounds. Then, they're in a certain order. So, these fifty sounds are the Japanese syllabary. That's hiragana / katakana, probably from back in the day when there were more sounds than there are now. So, the "fifty sounds in order" makes up aiueo order, where the "aiueo" is あいうえお representing the five columns.
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.
町名は五十音順にならんでいます。
The town names are listed in aiueo order.
この名ぼでは、学生の名前は名字で五十音順に記さいされています。
In this list, the students’ names are placed in aiueo order by surname.
日本で初めて五十音順に配列された国語辞典は、『和訓栞』です。
The first Japanese dictionary arranged in Japanese syllabary order was the "Wakun no shiori."