barb

(noun) an aggressive remark directed at a person like a missile and intended to have a telling effect. Synonyms: shot, shaft, slam, dig, jibe, gibe. Examples: "His parting shot was `drop dead'." "She threw shafts of sarcasm." "She takes a dig at me every chance she gets."

(noun) the pointed part of barbed wire.

(noun) a subsidiary point facing opposite from the main point that makes an arrowhead or spear hard to remove.

(noun) one of the parallel filaments projecting from the main shaft of a feather.

(verb) provide with barbs. Example: "Barbed wire."