holograph vs palimpsest

holograph and palimpsest both are nouns.

Word	Noun	Adjective	Verb	Adverb
holograph	Yes	No	No	No
palimpsest	Yes	No	No	No

As nouns, palimpsest is a hyponym of holograph; that is, palimpsest is a word with a more specific, narrower meaning than holograph:

holograph: handwritten book or document
palimpsest: a manuscript (usually written on papyrus or parchment) on which more than one text has been written with the earlier writing incompletely erased and still visible

Other hyponyms of holograph include codex, leaf-book, roll, scroll.

holograph (noun)	palimpsest (noun)
the intermediate photograph (or photographic record) that contains information for reproducing a three-dimensional image by holography	a manuscript (usually written on papyrus or parchment) on which more than one text has been written with the earlier writing incompletely erased and still visible
handwritten book or document