"fall into disuse, grow obsolete," 1801, from Latin obsolescere "to grow old, wear out, lose value, become obsolete," inchoative of obsolere "fall into disuse" (see obsolete). Related: Obsolesced; obsolescing.
This word has not obsolesced, although it is rarely used
obsess
obsessed
obsession
obsessive
obsidian
obsolesce
obsolescence
obsolescent
obsolete
obstacle
obstetric