harakiri vs seppuku

harakiri and seppuku both are nouns.

Word	Noun	Adjective	Verb	Adverb
harakiri	Yes	No	No	No
seppuku	Yes	No	No	No

As nouns, harakiri and seppuku are synonyms defined as:

harakiri and seppuku: ritual suicide by self-disembowelment on a sword; practiced by samurai in the traditional Japanese society

Other synonyms of harakiri include hara-kiri, harikari.

harakiri (noun)	seppuku (noun)
ritual suicide by self-disembowelment on a sword; practiced by samurai in the traditional Japanese society	ritual suicide by self-disembowelment on a sword; practiced by samurai in the traditional Japanese society