morosity

adjective

1. gloomily or sullenly ill-humored, as a person or mood.
2. characterized by or expressing gloom.

adjective

1. ill-tempered or gloomy

adj.1530s “gloomy,” from Latin morosus “morose, peevish, hypercritical, fastidious,” from mos (genitive moris) “habit, custom” (see moral (adj.)). In English, manners by itself means “(good) manners,” but here the implication in Latin is “(bad) manners.” Related: Morosity.