source: By trekphiler - Own work, CC BY-SA 3.0

1. no longer produced or used; out of date:

旧式の, 年代物の, 時代遅れの(outdated); すたれた; 使われなくなった

e.g. the disposal of old and obsolete machinery

e.g. the phrase was obsolete after 1625.

2. Biology (of a part or characteristic of an organism) less developed than formerly or in a related species; rudimentary; vestigial.

〘生物〙 痕跡だけの, 退化した.

cause (a product or idea) to be or become obsolete by replacing it with something new:

e.g. we're trying to stimulate the business by obsoleting last year's designs.

obsoletely adverb

obsoleteness | ˌäbsəˈlētnəs | noun

obsoletism | -ˈlēˌtizəm | noun

late 16th century: from Latin obsoletus ‘grown old, worn out’, past participle of obsolescere ‘fall into disuse’.