/ ˌɒbsəˈlesns; NAmE ˌɑːb-/ noun
[ U ] ( formal ) the state of becoming old-fashioned and no longer useful (= becoming obsolete ) :
products with built-in / planned obsolescence (= designed not to last long so that people will have to buy new ones)
► ob·so·les·cent / ˌɒbsəˈlesnt; NAmE ˌɑːb-/ adjective