We don't have synonyms for brown dwarfs yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are brown dwarf and brown dwarves.
(n) :
(astronomy) A starlike object that contracts to about the volume of Jupiter after its formation phase; its mass may range from several times that of Jupiter, such that it fuses deuterium, up to just below the threshold of sustained hydrogen fusion.
(n) :
(astronomy) A starlike object that contracts to about the volume of Jupiter after its formation phase; its mass may range from several times that of Jupiter, such that it fuses deuterium, up to just below the threshold of sustained hydrogen fusion.