Source : Webster's Revised Unabridged Dictionary (1913)

Loathsome \Loath"some\, a.
   Fitted to cause loathing; exciting disgust; disgusting.

         The most loathsome and deadly forms of infection.
                                                  --Macaulay.
   -- {Loath"some*ly}. adv. -- {Loath"some*ness}, n.