1. A person who provides a guarantee or endorsement for another person's debt or financial obligation
The bank required a guarantor to co-sign the loan.
O banco exigiu um avalista para assinar o empréstimo.
2. In commercial law, a person who signs a bill of exchange or promissory note as a guarantor
The avalista is legally responsible if the debtor defaults.
O avalista é legalmente responsável se o devedor não pagar.