This is the 722nd most frequent Italian word.
doppio
Double.
The word 'doppio' is used as an adjective to describe something that is doubled or appears twice, in this case, the rainbow.
Ho visto un arcobaleno doppio ieri.
I saw a double rainbow yesterday.
In this sentence, 'doppio' signifies a quantity multiplied by two, reflecting an increased amount or extent.
Questo errore ci dà il doppio del lavoro necessario.
This mistake gives us double the necessary work.
The word 'doppio' here characterizes a serving size, indicating 'double' the standard quantity.