Antonyms of adj four-year-old

1 sense of four-year-old

Sense 1
four-year-old -- (four years of age)

INDIRECT (VIA young) -> old -- ((used especially of persons) having lived for a relatively long time or attained a specific age; "his mother is very old"; "a ripe old age"; "how old are you?")

Similarity of adj four-year-old

1 sense of four-year-old

Sense 1
four-year-old -- (four years of age)
       => young (vs. old), immature -- ((used of living things especially persons) in an early period of life or development or growth; "young people")