Source : Webster's Revised Unabridged Dictionary (1913)

Lugubrious \Lu*gu"bri*ous\, a. [L. lugubris, fr. lugere to
   mourn; cf. Gr. ? sad, Skr. ruj to break.]
   Mournful; indicating sorrow, often ridiculously or feignedly;
   doleful; woful; pitiable; as, a whining tone and a lugubrious
   look.

         Crossbones, scythes, hourglasses, and other lugubrious
         emblems of mortality.                    --Hawthorne.
   -- {Lu*gu"bri*ous*ly}, adv. -- {Lu*gu"bri*ous*ness}, n.

Source : WordNet®

lugubrious
     adj : excessively mournful