This is the 7833rd most frequent Japanese word.
咲き
"咲き" means "blooming" or "blossoming."
Here, '咲きました' is a verb in past tense indicating the blooming of the cherry blossoms.
桜の花が満開に咲きました。
The cherry blossoms have bloomed fully.
In this sentence, '咲いている' represents the continuous action of blooming.
庭のバラがきれいに咲いている。
The roses in the garden are blooming beautifully.
'咲くこと' uses '咲く' in its dictionary form to describe the general concept of blooming.