under ... years of age; less than ... years old
Suffix attached to a number indicating an age threshold; used in formal or legal contexts to specify age limits.
Children under 6 years of age cannot use this attraction.
Those under 18 years of age must be accompanied by a guardian.
以下 means '... or below' and includes the stated number, while 未満 means 'under' and excludes it. For age, 18歳未満 means under 18, whereas 18歳以下 means 18 or under.
Standard kanji spelling using 歳 for age.
Simplified variant using 才, common in informal contexts or when 歳 is considered complex.
Compound of 歳 (sai, 'years of age') and 未満 (miman, 'less than, under').