guaiac wood vs guaiacum wood

guaiac wood and guaiacum wood both are nouns.

Word	Noun	Adjective	Verb	Adverb
guaiac wood	Yes	No	No	No
guaiacum wood	Yes	No	No	No

As nouns, guaiac wood and guaiacum wood are synonyms defined as:

guaiac wood and guaiacum wood: heartwood of a palo santo; yields an aromatic oil used in perfumes

guaiac wood (noun)	guaiacum wood (noun)
heartwood of a palo santo; yields an aromatic oil used in perfumes	heartwood of a palo santo; yields an aromatic oil used in perfumes