1. Third person plural present indicative of 'rebelar-se' - to rise up in opposition or resistance against authority, rules, or established norms
The citizens rebel against the oppressive government.
Os cidadãos rebelam-se contra o governo opressivo.
2. To resist or refuse to comply with something; to show reluctance or defiance
The teenagers rebel against their parents' rules.
Os adolescentes rebelam-se contra as regras dos pais.