This is the 12242nd most frequent Spanish word.
jumbo
"Jumbo" in Spanish refers to something very large or oversized.
In this sentence, 'jumbo' is used as an adjective to describe a very large size of the popcorn pack.
Compré un paquete jumbo de palomitas en el cine.
I bought a jumbo pack of popcorn at the cinema.
Here, 'jumbo' is describing a type of airplane, specifically a very large one.
El avión jumbo despegó justo a tiempo.
The jumbo airplane took off just in time.
'Jumbo' in this instance again emphasizes the unusual large size of the plush toy.