1. First person singular preterite of 'amassar' - to knead dough or similar material
I kneaded the dough for the bread.
Amassei a massa para o pão.
2. First person singular preterite of 'amassar' - to accumulate or gather (money, wealth, etc.)
He amassed a fortune over the years.
Amassei uma fortuna ao longo dos anos.
3. To crush, compress, or squash something
I crushed the tin can with my hands.
Amassei a lata de alumínio com as mãos.