In clover means living in comfort, ease, or prosperity. If someone is in clover, life is going well for them, especially in a way that suggests plenty or good fortune.
The expression comes from farming life. Clover was a rich, nourishing plant for grazing animals. An animal feeding in a field full of clover had abundant food and was in an enviable position. That image of plenty helped give the phrase its modern meaning.
Today, people use it to talk about comfort, success, or favorable circumstances. It often has a slightly informal tone.
- After years of struggling, they were finally in clover.
- With free housing and meals included, the interns were in clover for the summer.
The phrase is not usually used for a brief moment of happiness. It more often suggests a comfortable situation that lasts for some time. In other words, it is closer to prospering than simply feeling pleased.