在英语中，当人们感到快乐、开心或笑得很开心时，我们通常会用 "laugh" 或 "laughing" 这两个词来描述这种感觉。例如：

"She was laughing so hard that she had tears in her eyes." (她笑得那么开心，以至于眼睛里都流出了眼泪。)

"I couldn't stop laughing at his jokes." (我笑得停不下来，因为他的笑话太好笑了。)

"They were all laughing and having a good time." (他们都在笑着玩得很开心。)

这些词的来源可以追溯到古英语时期的 "hlæhhan" 和 "hlæghing"，在中古英语时期演变成了 "laugian" 和 "laugung"，最终在现代英语中变成了 "laugh" 和 "laughing"。

还有一些其他用来形容快乐、开心或笑得很开心的词，如 "happy"、"jolly" 和 "merry"。例如：

"She had a happy laugh that always made me smile." (她有一种让我笑的开心的笑声。)

"He was in a jolly mood and couldn't stop laughing." (他心情很好，笑得停不下来。)

"They were all feepng merry and laughed at everything." (他们都感到很开心，对任何事情都笑得很开心。)