barcode UK /ˈbɑː.kəʊd/US /ˈbɑɹ.koʊd/noun 3verb 1forms 3 noun3 •Any set of machine-readable parallel bars or concentric circles, varying in width, spacing, or height, encoding information according to a symbology. •(slang) An instance of self-harm, typically with multiple parallel cuts along a line, similar in form to a machine barcode. •A portion of a gene that identifies a particular species. verb1 •To apply a barcode (machine-readable code) to. formsbarcoded · barcoding · barcodes