Four-year-old is a term that describes a child who has reached the age of four years. There are numerous synonyms that can be used instead of this term. These include preschooler, toddler, youngster, little one, small fry, and junior. These synonyms describe this age range in various ways and can be used interchangeably depending on the context. Preschooler emphasizes the educational stage of a child's development, while toddler highlights their emerging independence. Youngster and little one are more general terms for young children. Small fry has a more playful connotation. Junior is often used in the context of sports or academic programs. Overall, these synonyms can help add variety and nuance to descriptions of children at this age.