spike heel vs stiletto heel

spike heel and stiletto heel both are nouns.

Word	Noun	Adjective	Verb	Adverb
spike heel	Yes	No	No	No
stiletto heel	Yes	No	No	No

As nouns, spike heel and stiletto heel are synonyms defined as:

Other synonyms of spike heel include spike.

spike heel (noun)	stiletto heel (noun)
a very high narrow heel on women's shoes	a very high narrow heel on women's shoes