seppuku vs suicide

seppuku and suicide both are nouns.

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

As nouns, suicide is a hypernym of seppuku; that is, suicide is a word with a broader meaning than seppuku:

seppuku: ritual suicide by self-disembowelment on a sword; practiced by samurai in the traditional Japanese society
suicide: the act of killing yourself

Other hypernyms of seppuku include self-annihilation, self-destruction.

seppuku (noun)	suicide (noun)
ritual suicide by self-disembowelment on a sword; practiced by samurai in the traditional Japanese society	the act of killing yourself
	a person who kills himself intentionally