■ adjective
1》 no longer produced or used; out of date.
2》 Biology less developed than formerly or in a related species; rudimentary; vestigial.
■ verb chiefly US cause (a product or idea) to become ~ by replacing it with something new.
Derivatives
~ly adverb
~ness noun
obsoletism noun
Origin
C16: from L. obsoletus 'grown old, worn out', past participle of obsolescere 'fall into disuse'.