Obscene means offensive, especially about sex. Obscene material, obscene language, an obscene gesture.
In English law it has a specific and much-argued definition about tending to deprave and corrupt, and obscenity trials have been landmarks in the history of publishing. The second sense is about outrage rather than sex: obscene wealth, obscene profits, an obscene waste — where obscene means morally shocking. Note obscenity, which means both the quality and a swear word; and obscure, which sounds similar and is unrelated.
1adjectiveobsceneOffensive, especially about sex.
“The book was tried for obscene content and sold about two million.”
2adjectivemorallyMorally shocking.
“The waste was obscene and nobody was held responsible.”
obscene is a quality of offensiveness.
Latin obscenus meant ill-omened or repulsive, and the Romans used it of anything offensive to the gods. Its deeper origin is disputed, and the sexual narrowing is entirely an English development.
Proto-Indo-European
*ḱweyn- — to make dirty, soil; filth; mud
Latin
obscēnus
Middle French
obscene
English, today
obscene
Built from
From Middle French obscene (modern French obscène (“indecent, obscene”)), and from its etymon Latin obscēnus, obscaenus (“inauspicious; ominous; disgusting, filthy; offensive, repulsive; indecent, lewd, obscene”). The further etymology is, but may be from ob- + caenum (“dirt, filth; mire, mud”) (possibly ultimately from Proto-Indo-European ḱweyn- (“to make dirty, soil; filth; mud”)) or scaevus (“left, on the left side; clumsy; (figurative) unlucky”) (from Proto-Indo-European skeh₂iwo-). If from caenum, the unexpected extra -s- may be from a variant form of the original PIE root; a similar -s- exists in ex-.
Etymology from Wiktionary, CC BY-SA