年とし子ご

noun

child born within a year of another; children born in consecutive years

Refers to siblings born less than a year apart, or children born one after another with a small age gap. Often used in the context of family planning or describing sibling relationships.

• うちの子こは年とし子ごで、上うえがまだ一いっ歳さいにならないうちに下したが生うまれました。

  Our children are born within a year of each other; the younger one was born before the older one turned one.

• 年とし子ごの兄きょう弟だいはよく双ふた子ごと間ま違ちがえられる。

  Siblings born in consecutive years are often mistaken for twins.