This is the 3959th most frequent Japanese word.
ジャンボ
"ジャンボ" means "jumbo" or "large" in English, often used for big things or greetings like "Hello (Jumbo)."
In this context, ジャンボ modifies the type of jet to indicate its large size, often referring to commercial wide-body aircraft.
ジャンボジェット機は非常に大きい飛行機です。
A jumbo jet is a very large aircraft.
Here ジャンボ is used as an adjective to describe the size of the ice cream, implying it is extra large.
そのジャンボサイズのアイスクリームを食べてみたいです。
I want to try that jumbo-sized ice cream.
In this example, ジャンボ is used as a proper noun, likely being a nickname or a unique name assigned to a person.