Disk, Flying Saucer
noun, の adjective
A round tray is a disk, though if it goes through the air it becomes a flying saucer.
えんばん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
しばらくすると、ジェームズは円盤を脇に抱えて戻ってきて、UFOを見つけたんだと言いました。
After a while, James came back with a disk under his arm and told us he found a UFO.