OBSOLETE. That which is no longer used. Disused; neglected; not observed. The term is applied to statutes which have become inoperative by lapse of time, either because the reason for their enactment has passed away, or their subject-matter no longer exists, or they are not applicable to changed circumstances, or are tacitly disregarded by all men, yet without being expressly abrogated or repealed. (Blacks Law 4th Edition)
ob·so·lete
[ˌäbsəˈlēt]
adjective
obsolete (adjective) (Oxford Dictionary)
no longer produced or used; out of date:
"the disposal of old and obsolete machinery" · "the phrase was obsolete after 1625"
biology
(of a part or characteristic of an organism) less developed than formerly or in a related species; rudimentary; vestigial.