"Xystus" could be an option for an ancient Rome ABC book. Xystus was a type of open portico used in ancient Roman architecture, typically used for exercise or walking.
Octavian Caesar (Augustus)
Y is for the letter Y. The letter Y, along with K & Z, were not part of the original Latin alphabet.
villages
Isis one of the goddeses of ancient Egypt
Eternal life and farming
Fertilization
zeal
Sit on my face plz
An ABC book is a book, often written for children, containing prompts to teach them letters of the alphabet.
"Yield" could be a good choice for a Y word in an ABC book on energy. It relates to the amount of energy produced by a system or process.
AN ABC book report for forged by fire is to give your main opinion for it and how you felt about the book
Use Yankee. It might help.