From Latin atrōx (savage, fierce, ferocious, atrocious), from āter (black, dark) — possibly combined with a root related to ōculus (eye), giving a literal sense of 'dark-eyed' or 'having a fierce look'. Via Old French atroce into English in the mid-16th century, initially in the strong moral sense. The weakened informal sense ('extremely bad in quality') developed later, particularly in British English from the 19th century onward.