The Collaborative International Dictionary of English v.0.48:

Actinomycosis \Ac`ti*no*my*co"sis\
   ([a^]k`t[i^]*n[-o]*m[imac]*k[=o]"s[i^]s), n. [NL.] (Med.)
   A chronic infectious disease of cattle and man due to
   infection with actinomycetes, especially by Actinomyces
   bovis in cattle and by Actinomyces israeli or Arachnia
   propionica in man. It is characterized by hard swellings
   usually in the mouth and jaw. In man the disease may also
   affect the abdomen or thorax. In cattle it is called also
   lumpy jaw or big jaw.
   [Webster 1913 Suppl. + AS]

WordNet (r) 3.0 (2006):

actinomycosis
    n 1: disease of cattle that can be transmitted to humans;
         results from infection with actinomycetes; characterized by
         hard swellings that exude pus through long sinuses