kelpie vs evil spirit

kelpie and evil spirit both are nouns.

Word	Noun	Adjective	Verb	Adverb
kelpie	Yes	No	No	No
evil spirit	Yes	No	No	No

As nouns, evil spirit is a hypernym of kelpie; that is, evil spirit is a word with a broader meaning than kelpie:

kelpie: (Scottish folklore) water spirit in the form of a horse that likes to drown its riders
evil spirit: a spirit tending to cause harm

kelpie (noun)	evil spirit (noun)
an Australian sheepdog with pointed ears	a spirit tending to cause harm
(Scottish folklore) water spirit in the form of a horse that likes to drown its riders