We don't have synonyms for dark matters yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are dark matter, back matters and dark pattern.
(n) :
(astronomy, astrophysics, loosely) Matter which cannot be detected by its radiation but whose presence is inferred from gravitational effects.
(n) :
(particle physics, cosmology, strictly) Matter which has mass but which does not readily interact with normal matter except through gravitational effects.
(n) :
(biology, informal) Unclassified or poorly understood genetic material.
(n) :
(astronomy, astrophysics, loosely) Matter which cannot be detected by its radiation but whose presence is inferred from gravitational effects.
(n) :
(particle physics, cosmology, strictly) Matter which has mass but which does not readily interact with normal matter except through gravitational effects.
(n) :
(biology, informal) Unclassified or poorly understood genetic material.