Synonyms for the term "under age" encompass multiple expressions that refer to individuals who are legally considered too young for a specific activity or responsibility. An alternative term often used is "minor", which refers to someone below the legal age of adulthood. The phrase "not of legal age" is another common synonym, emphasizing the lack of legal validity for certain actions. Additionally, the term "juvenile" is employed when discussing individuals below the age of majority in the context of legal proceedings. Other synonyms for "under age" include "youthful", "immature", "adolescent", and "youngster", which emphasize the younger age bracket of individuals in question. Consequently, these terms can be used interchangeably to describe individuals who have not yet reached the legal age for a particular activity or responsibility.