of or relating to practice or action: practical mathematics. consisting of, involving, or resulting from practice or action: a practical application of a rule. of, relating to, or concerned with ordinary activities, business, or work: a habitual dreamer, who can't be bothered with practical affairs.
With the oldest of the Baby Boomers turning 65 this year, the question of when one becomes a senior citizen is a topic of interest to a new generation.
For most purposes, you become an adult when you turn 18, an age established by The Age of Majority Act. However, other ages can be important depending on what legal issues are involved. For example, under Michigan law a person is considered an adult for purposes of the criminal law at age 17.