noun
flower vase; vase
A container for displaying flowers, often used in ikebana or decorative contexts.
花器に季節の花を生ける。
I arrange seasonal flowers in a vase.
花瓶 is the common everyday word for a flower vase, while 花器 is a slightly more formal or artistic term often used in ikebana.
Compound of 花 (flower) and 器 (container, vessel).