歳 (Sai) is a Japanese counter meaning “... years old, age (of) ...”.
Meanings
- counter... years old; age (of) ...
Examples
彼女は五歳です。
She is five years old.
父は母より２歳若い。
My father is two years younger than my mother is.
娘はやっと１５歳です。
My daughter is barely fifteen.
Sentences from Tatoeba (CC BY 2.0 FR).