The Collaborative International Dictionary of English v.0.48:

Aden ulcer \A"den ul"cer\ ([aum]"den [u^]l"s[~e]r or [=a]"den
   [u^]l"s[~e]r). [So named after Aden, a seaport in Southern
   Arabia, where it occurs.] (Med.)
   One of the numerous names of the lesion of Old World
   cutaneous leishmaniasis. Called also Aleppo boil, Aleppo
   button, Aleppo evil, Bagdad boil, Biskra boil, Cochin
   China ulcer, Delhi boil, Jerico boil, Oriental boil,
   Oriental sore, Persian ulcer, tropical ulcer, etc.
   [Webster 1913 Suppl. + AS]

The Collaborative International Dictionary of English v.0.48:

Boil \Boil\, n. [Influenced by boil, v. See Beal, Bile.]
   A hard, painful, inflamed tumor, which, on suppuration,
   discharges pus, mixed with blood, and discloses a small
   fibrous mass of dead tissue, called the core.
   [1913 Webster]

   A blind boil, one that suppurates imperfectly, or fails to
      come to a head.

   Delhi boil (Med.), a peculiar affection of the skin,
      probably parasitic in origin, prevailing in India (as
      among the British troops) and especially at Delhi.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Delhi boil
    n 1: leishmaniasis of the skin; characterized by ulcerative skin
         lesions [syn: cutaneous leishmaniasis, Old World
         leishmaniasis, oriental sore, tropical sore, Delhi
         boil, Aleppo boil]