to trust, to rely on
Mira que fiarse de su mujer un tipo listo como tú.
A smart guy like you, actually trusting his wife.
— Carandiru (2003)
No hay que fiarse de las apariencias.
You can't judge by appearances.
A Tom no le gusta fiarse de otros.
Tom doesn't like relying on others.
No es cuestión de fiarse, guardia.
It's not a matter of trusting anyone, guard.
— Ladrón de bicicletas (1948)
Hablando francamente, él no es de fiarse.
Frankly speaking, he's not to be trusted.