osÂ·teÂ·opÂ·aÂ·thy. n. 1. A system of medicine practiced by licensed osteopathic physicians that involves palpation and noninvasive manipulation of the musculoskeletal system in the diagnosis and treatment of physical dysfunction, in conjunction with other medical, surgical, pharmacological, and therapeutic procedures.
Average Age of Presidents. The majority of the presidents were between the ages of 50 and 59 when they were elected into office. The youngest elected president was John F. Kennedy at age 43. The oldest elected president was Ronald Reagan at age 69.
When Donald Trump is inaugurated in exactly two weeks' time, he'll become the oldest elected president in U.S. history. The average age of all 44 U.S. presidents who have taken office is just over 55 while Trump is 70.