peremptory Look up peremptory at Dictionary.com
"decisive," 1513, legal term, from Anglo-Fr. peremptorie, from M.Fr. peremtoire, from L. peremptorius "destructive, decisive, final," from peremptor "destroyer," from perimpere "destroy, cut off," from per- "away entirely, to destruction" + emere "to take" (see exempt). Of persons or their words, "certain, assured, brooking no debate," 1586.