What's the adjective for obsoleter? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs obsolesce and obsolete which may be used as adjectives within certain contexts.
obsolete
(of words, equipment, etc.) No longer in use; gone into disuse; disused or neglected (often by preference for something newer, which replaces the subject).
(biology)Imperfectly developed; not very distinct.