We don't have synonyms for obselete yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are obsolete, absolete and osselet.
°(of words, equipment, etc.) no longer in use; gone into disuse; disused or neglected (often by preference for something newer, which replaces the subject).
°(of words, equipment, etc.) no longer in use; gone into disuse; disused or neglected (often by preference for something newer, which replaces the subject).