This is the 505th most frequent Italian word.
peso
"Peso" in Italian means "weight" in English.
Here, 'peso' refers to the physical weight of an object, which is a common noun usage.
Il peso della scatola è notevole.
The weight of the box is considerable.
In this case, 'peso' is used metaphorically to describe the burden or stress of responsibilities.
Il peso delle responsabilità lo opprime.
The weight of responsibilities oppresses him.
Here, 'peso' is used in the plural form 'pesi' to refer to weights or weightlifting equipment.