a. (Med.) 1. Pertaining to, or connected with, diphtheria. [ 1913 Webster ]
2. Having characteristics resembling those of diphtheria; as, diphtheritic inflammation of the bladder. [ 1913 Webster ]
a. (Med.) Destructive to, or hindering the growth of, diphtheria bacilli. -- n. An antidiphtheritic agent. [ Webster 1913 Suppl. ]