barb

barb (http://definr.com/barb)

     n 1: an aggressive remark directed at a person like a missile and
          intended to have a telling effect; "his parting shot was
          `drop dead'"; "she threw shafts of sarcasm"; "she takes
          a dig at me every chance she gets" [syn: shot, shaft,
           slam, dig, jibe, gibe]
     2: the pointed part of barbed wire
     3: a subsidiary point facing opposite from the main point that
        makes an arrowhead or spear hard to remove
     4: one of the parallel filaments projecting from the main shaft
        of a feather
     v 1: provide with barbs; "barbed wire"
     2: provide with barbs, as of fences, for example; "barbed wire"