Entry 1 sense Webster, 1913 Seppuku /sĕpʹo͞o-ko͞o/ · Sep·pu·ku · IPA /ˈsɛ.pu(ˌ)ku/ 01 n. Same as Hara-kiri. 1. Same as Hara-kiri. See: Hara-kiri “Seppuku, or hara-kiri, also came into vogue.” — W. E. Griffis.