The term 'IMPORTANT AGE' can be broken down into four crossword solutions: ERA (3 letters), EPOCH (5 letters), EIGHTEEN (8 letters), and TEEN (4 letters). An ERA is a period of time in history that is defined by certain characteristics, such as a political or cultural movement. An EPOCH is a longer period of time than an ERA, usually lasting thousands or millions of years. EIGHTEEN is a number that is often associated with adulthood, as it is the age when a person is legally considered an adult in many countries. Teen is a shortened version of the word teenager, which is used to describe someone between the ages of 13 and 19.