The traditional Chinese character for "乐" in "happy":

The meaning of "happy": to feel happy or satisfied: ~'s smile. Happy birthday to you~.

Sentence:

1. In the bright spring days, we study happily.

2. The whole family raised a toast to wish grandpa a happy birthday and long and healthy life.

3. The happiest people are those who are too busy to notice whether they are happy or not.

Extended information

Synonyms of "happiness": joy, joy

1. Joy [huān lè]

Happiness (multiple references to Collective): Singing sounds came and went in the square.

Citation and explanation: Act 3 of Cao Yu's "Wang Zhaojun": "I came here for the happiness of the two families."

2. Happy [kāi xīn]

1. Mood is happy and comfortable: everyone is together, talking and laughing, very happy~.

2. Tease others to make yourself happy: don’t tease them~.

Citation explanation: The first scene of Cao Yu's "Sunrise": "Hei San: (laughing with him) Mr. Pan, don't be happy with us."