See obsolete in Webster's New World College Dictionary
adjective
no longer in use or practice; discarded
no longer in fashion; out-of-date; passé
Biol. rudimentary or poorly developed as compared with its counterpart in other individuals of a related species, the opposite sex, etc.; vestigial: said of an organ, etc.
Outmoded in design, style, or construction: an obsolete locomotive.
Biology Vestigial or imperfectly developed, especially in comparison with other individuals or related species; not clearly marked or seen; indistinct. Used of an organ or other part of an animal or plant.