This is the 682nd most frequent Japanese word.
器
Utensil, container, vessel, or capacity (mental or physical).
器 here metaphorically refers to 'capacity' or 'capability'.
彼は芸術家としての器が大きい。
He has great talent as an artist.
器 metaphorically represents a medium or means for something.
この町は文化交流の器の役割を果たしている。
This town serves as a vessel for cultural exchange.
器 is used in its literal sense, meaning a bowl or container.