Black bile — phantom fluid of ancient medicine — haunts English and Spanish at the syllable level, a physician's theory surviving two millennia into a poet's lexicon. 忧郁 never mentions medicine: it reaches for the phenomenology directly — heart overburdened, something fragrant sealed and unable to escape. English softened the word through Old French; Spanish kept the Latin form's learned composure intact. Esperanto simply inherited the pan-European shell, as though naming the condition were enough.
Functions as both noun and adjective in modern English. The -choly spelling preserves Greek χολή (bile) visible through the Latin and French transmission.
Learned borrowing (cultismo) from Latin melancholia; tonic stress on -í- follows standard Spanish patterns for words of Greek-Latin scholarly origin.
The heart (忄) burdened by what presses hardest (尤). Simplified from traditional 憂, which showed an entire person — bowed head, slow dragging feet, heart at center — consumed by sorrow from crown to sole.
Phonetic simplification of traditional 鬱, which depicted fragrant ceremonial herb-wine vapors (鬯) rising within a dense grove (林) yet sealed inside a vessel — something alive and aromatic that cannot escape. The simplified form 郁 preserves the sound, not the picture.
Traditional compound 憂鬱 (yōuyù) remains standard in Taiwan and literary contexts; simplified 忧郁 is mainland standard. Both characters appear independently in classical poetry centuries before the compound solidified as a unit.
Zamenhof-era borrowing of the pan-European learned term. Native alternatives exist: malĝojo (un-joy, unmarked sadness) and tristeco (quality of sadness); melankolio carries the more specific literary, Romantic-register meaning.
Perhaps the untranslatable thing is not any word but the quiet suspicion — shared across every script — that black bile was always a metaphor for something the body already knew how to feel without a name.