"person afflicted with melancholy, one who is affected with mental gloom," 1819, from melancholia. Earlier in same sense were melancholian (1630s), melancholist (1590s), melancholic (1580s).
Entries linking to melancholiac
melancholia n.
"mental condition characterized by great depression, sluggishness, and aversion to mental action," 1690s, from Modern Latin melancholia (see melancholy).