impetigoPronunciation: /ˌɪmpɪˈtʌɪgəʊ/Definition of impetigo noun [mass noun] a contagious bacterial skin infection forming pustules and yellow crusty sores: the children all have impetigoThis disease is caused by the bacteria Streptococcus pyogenes or S. aureus Origin: late Middle English: from Latin, from impetere 'to assail, attack'impetigo in other Oxford dictionaries Definition of impetigo in the US English dictionary