This is the 5632nd most frequent Japanese word.
しあわせ
Happiness.
The word 'しあわせ' is used as a noun meaning 'happiness,' modified by 'な' to describe a type of time.
しあわせな時間を過ごしました。
I spent happy and fulfilling moments.
Here, 'しあわせ' is used as a noun referring to someone's state of happiness or personal fulfillment.
あなたのしあわせを祈っています。
I pray for your happiness.
In this sentence, 'しあわせ' functions as part of the descriptive phrase 'しあわせそうな,' which means 'seemingly happy.'