Source : WordNet®

sass
     n : an impudent or insolent rejoinder; "don't give me any of
         your sass" [syn: {sassing}, {backtalk}, {back talk}, {lip},
          {mouth}]
     v : answer back in an impudent or insolent manner; "don't sass
         me!"; "The teacher punished the students who were sassing
         all morning";