noun
all kinds of flowers; many flowers
Literary or poetic term for a profusion of blossoms; often used in set phrases like 百花繚乱 (a hundred flowers blooming in profusion).
春になると、庭に百花が咲き乱れる。
In spring, all kinds of flowers bloom in profusion in the garden.
百花繚乱の美しさに圧倒された。
I was overwhelmed by the beauty of a hundred flowers blooming in profusion.
Compound of 百 (ひゃく, 'hundred') and 花 (か, 'flower'), with the regular sound change ひゃくか → ひゃっか. The 'hundred' here is figurative for 'many' or 'all kinds'.