How to say "nephew" in Japanese

• 甥おいJLPT N1approx.Common
  nounThe common word for a nephew — the son of one's brother or sister. Use this when simply stating the family relationship.
  私のおいは卵たまごに対たいしてアレルギー体質たいしつだ。↗

  My nephew is allergic to eggs.
• 甥っ子おいっこ
  nounA familiar variant of 甥 with the same meaning; less common, and at home in casual conversation about one's nephew.
• 猶子ゆうし
  nounA nephew treated like a son, or another child considered as one's own; a less common term, not the everyday word for a nephew.

Use 甥 for a nephew in ordinary contexts; 「甥っ子」 is a familiar variant of it; 猶子 means a nephew treated like a son or another child considered as one's own.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 甥おいnephew
• 甥っ子おいっこnephew
• 猶子ゆうしnephew (like a son)
• 甥御おいご(another person's) nephew