Definition of barcodes:
(n) :
Any set of machine-readable parallel bars or concentric circles, varying in width, spacing, or height, encoding information according to a symbology.
(n) :
(genetics) A portion of a gene that identifies a particular species.
(n) :
(self-harm, slang) An instance of self-harm, typically with multiple parallel cuts along a line, similar in form to a machine barcode.