noun
(US black humor)
1Medicine
The humour black bile; an unnatural, disease-causing humour derived from or resembling this; now historical and rare. Later also (in extended use): a depressed, angry, or sullen mood.2Comedy, satire, etc., that presents tragic, distressing, or morbid situations in humorous terms; humour that is ironic, cynical, or dry; gallows humour.
Origin
Late Middle English; earliest use found in John Trevisa (c1342–?1402), translator. From black + humour. Compare atrabile, black bile, and the Latin and Greek parallels cited at those entries. Compare Italian (now hist.) umore nero black bile.
Are You Learning English? Here Are Our Top English Tips