in a way that is not formal or official

They've agreed informally to separate. 他们已经非正式地同意分开了。

After trying informally to help, she finally took legal steps to become the boys' guardian. 在尝试了非正式地提供帮助后，她最终采取法律流程成为了男孩们的监护人。

in a way that is suitable when you are with friends and family but not for official occasions

It's an outdoor party, so dress informally. 这是个户外聚会，所以可以穿得随意些。

Samuel is known informally as "Sam" by most of his colleagues. 塞缪尔的大多数同事都亲切地叫他“山姆”。