obelisk vs grapheme

obelisk and grapheme both are nouns.

Word	Noun	Adjective	Verb	Adverb
obelisk	Yes	No	No	No
grapheme	Yes	No	No	No

As nouns, grapheme is a hypernym of obelisk; that is, grapheme is a word with a broader meaning than obelisk:

obelisk: a character used in printing to indicate a second cross reference or footnote when the asterisk has already been used
grapheme: a written symbol that is used to represent speech

Other hypernyms of obelisk include character, graph, graphic symbol.

obelisk (noun)	grapheme (noun)
a stone pillar having a rectangular cross section tapering towards a pyramidal top	a written symbol that is used to represent speech
a character used in printing to indicate a second cross reference or footnote when the asterisk has already been used