noun
small container; person of small capacities
Literal meaning is a physically small container. Figuratively, it describes a person of limited ability, narrow-mindedness, or pettiness, often contrasted with 大器 (たいき).
この小器には調味料を入れてください。
Please put the seasoning in this small container.
彼は小器で、部下の成功を素直に喜べない。
He is a small-minded person and cannot honestly celebrate his subordinates' success.