Guy vs simulacrum

Guy and simulacrum both are nouns.

Word	Noun	Adjective	Verb	Adverb
Guy	Yes	No	No	No
simulacrum	Yes	No	No	No

As nouns, simulacrum is a hypernym of Guy; that is, simulacrum is a word with a broader meaning than Guy:

Guy: an effigy of Guy Fawkes that is burned on a bonfire on Guy Fawkes Day
simulacrum: a representation of a person (especially in the form of sculpture)

Other hypernyms of Guy include effigy, image.

Guy (noun)	simulacrum (noun)
an effigy of Guy Fawkes that is burned on a bonfire on Guy Fawkes Day	a representation of a person (especially in the form of sculpture)
	an insubstantial or vague semblance