1. An unexplored, unmapped, or unknown geographical area; a region not yet documented or charted
The interior of the rainforest remained a blank space on the map for centuries.
O interior da floresta tropical permaneceu um espaço em branco no mapa por séculos.
2. Figuratively, an area of knowledge, experience, or understanding that is unknown or unexplored
Medieval history was a blank space on the map of his education.
A história medieval era um espaço em branco no mapa de sua educação.