1.. ~ sb (of / about sth) to tell sb about sth, especially in an official way: [vn] Please inform us of any changes of address. The leaflet informs customers about healthy eating. He went to inform them of his decision. Inform me at once if there are any changes in her condition. Have the police been informed? [vn that] I have been reliably informed (= somebody I trust has told me) that the couple will marry next year.