The term "45th (Ordinal)" refers to the position of something in a sequential order, specifically indicating that it is the forty-fifth item. Ordinal numbers are used to denote rank or position, such as in a race or a list. For example, if a runner finishes in 45th place, they are the 45th person to cross the finish line. In various contexts, the 45th can refer to events, anniversaries, or even political positions. For instance, the 45th President of the United States was Donald Trump, who served from January 20, 2017, to January 20, 2021.