noun
topper; item placed on top
A katakana noun corresponding to “topper.” In Japanese it is often encountered in product names and compounds for something added on top, such as a cake decoration or a mattress top layer.
誕生日用のケーキトッパーを買った。
I bought a cake topper for the birthday.
寝心地を変えるために、マットレスの上にトッパーを敷い
I laid a topper on the mattress to change how it feels to sleep on.