ob·so·les·cent \| ̷ ̷ ̷ ̷|lesənt\adjective Etymology: Latin obsolescent-, obsolescens, present participle of obsolescere 1.: going out of use : falling into disuse especially as unable to compete with something more recent < animal transport is largely obsolescent > 2.: becoming obsolete; especially: vestigial • ob·so·les·cent·lyadverb