This is the 342nd most frequent Arabic word.
رئيس
"رئيس" means "chief," "leader," or "president" in English.
In this sentence, 'رئيس' means the president or leader of an organization, specifically the one in charge of a company.
رئيس الشركة يزور المصنع.
The company's president is visiting the factory.
Here, 'رئيس' refers to a political leader, specifically the elected leader of a country.
الرئيس المنتخب سيؤدي اليمين غدًا.
The elected president will be sworn in tomorrow.
In this context, 'رئيسة' is derived from 'رئيس' and acts as an adjective meaning 'main' or 'principal', describing the point of focus.