"melancholic," 1725, from Medieval Latin atrabilarius; an alternative of atrabilious (q.v.). Other alternatives are, or were, atrabilarious (1680s), atrabilarian (1670s), atrabilaric (1620).
Entries linking to atrabiliary
atrabilious adj.
"affected by melancholy," 1650s, from Latin atra bilis, translating Greek melankholia "black bile" (see melancholy; also compare bile). Atra is fem. of ater "black, dark, gloomy," and is perhaps "blackened by fire," from PIE root *ater- "fire." Related: Atrabiliousness.
*ater-
*āter-, Proto-Indo-European root meaning "fire." It forms all or part of: atrabiliary; atrabilious; atrium; atrocious.
It is the hypothetical source of/evidence for its existence is provided by: Old Persian atar "fire;" Latin ater "black" ("blackened by fire"), atrox "frightful" ("of fiery or threatening appearance").