precedent
noun |ˈpresəd(ə)nt|
an earlier event or action that is regarded as an example or guide to be considered in subsequent similar circumstances: there are substantial precedents for using interactive media in training | breaking with all precedent.
president |ˈprez(ə)dəntˈprezəˌdent|
noun
1 the elected head of a republican state: the Irish president | [as title] : President Kennedy.
• the head of a society, council, or other organization: the president of the European Community.