unknown quantity

• Persona o cosa cuyas características, capacidades o potencial aún no se conocen o comprenden, lo que suele implicar incertidumbre o imprevisibilidad.

A person or thing whose characteristics, abilities, or potential are not yet known or understood, often implying uncertainty or unpredictability.

1. Unpredictable person or thingB2formal

   A person or thing whose characteristics, abilities, or behavior are not yet known or understood.

   incógnita

   • The new manager is still an unknown quantity to the team.
   • In this experiment, the chemical reaction is an unknown quantity.
   • His performance in the final match remains an unknown quantity.