How to say "brother-in-law" in Japanese

• 義兄ぎけいCommon
  nounCovers a brother-in-law who is older: the spouse's older brother, or the husband of one's older sister. The 義 element marks the relationship as one by marriage rather than blood.
  義兄ぎけいは些細ささいなことですぐ怒おこり出だす。↗

  My brother-in-law is ready to lose his temper at trifles.
• 義弟ぎていCommon
  nounCovers a brother-in-law who is younger: the spouse's younger brother, or the husband of one's younger sister. The 義 element marks the tie as one by marriage rather than blood.
  まさか惚ほれたんですか。認みとめん、認みとめんぞ。あの男おとこを義弟ぎていになるなんて、僕ぼくは絶対ぜったいいやです！↗

  You haven't fallen in love, have you!? I won't have it! Having that man become my brother-in-law; I absolutely hate that!
• 兄あにJLPT N5approx.Common
  nounThe plain word 'older brother', which can also refer to the spouse's older brother or an older sister's husband when you speak of him simply as an older brother, without explicitly marking the in-law relationship.
• 弟おとうとJLPT N5approx.Common
  nounThe plain word 'younger brother', which can likewise refer to the spouse's younger brother or a younger sister's husband when you speak of him simply as a younger brother, without marking the in-law relationship.

Choose 義兄 or 義弟 for a brother-in-law by relative age, and the plain 兄 or 弟 when speaking of him as simply one's (or the spouse's) older or younger brother.

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

• 義兄ぎけいbrother-in-law (spouse's older brother or older sister's husband)
• 義弟ぎていbrother-in-law (spouse's younger brother or younger sister's husband)
• 小舅こじゅうとbrother-in-law
• 義兄弟ぎきょうだいbrother-in-law
• 相婿あいむこbrother-in-law
• お義兄さんおにいさんbrother-in-law (spouse's older brother or older sister's husband)
• 兄あにbrother-in-law (spouse's older brother or older sister's husband)
• 弟おとうとbrother-in-law (spouse's younger brother or younger sister's husband)