The adjective "tangential" means loosely related to, digressing from the main point but still partly related. This is closest in meaning to "extraneous" which means irrelevant, unrelated, incidental. Additionally, "limpid" means clear, able to be seen through; "impetuous" means done without forethought or appropriate care, rash and reckless; "artificial" means fake, not genuine, constructed to mimic something real; "ornery" means grumpy, bad-tempered.

The adjective "glib" means (of speech) "insincere" and disingenuous. Additionally, "outlawed" means banned, forbidden, not allowed; "sacrilegious" means blasphemous, offensive to a religion; "ornate" means elaborately decorated, adorned and embellished; "abstract" means not concrete, related to something theoretical or intangible.

The adjective "propitious" means favorable, auspicious, (of circumstances) lucky and indicating a good chance for success. This is closest in meaning to "providential" which means favorable, divinely ordained to happen. Additionally, "garbled" means mixed up; "imbued" means filled with; "exasperated" means frustrated by, deeply irritated by; "dynamic" means energetic, powerful, exciting or forceful.

The adjective "incontrovertible" means not able to be denied, undeniable, not able to be disputed, irrefutable. Additionally, "unflappable" means calm and controlled in a crisis, not able to be stressed or unnerved; "untimely" means occurring at a bad time; "inauspicious" means not promising, an unfortunate beginning that suggests further failure; "inopportune" means unsuitable, not favorable, untimely.

The adjective "germane" means relevant to, applicable, able to be applied to. Additionally, "inexplicable" means unable to be explained; "impeccable" means flawless, perfect; "edible" means able to be eaten; "formidable" means daunting, awe-inspiring and intimidating.

The adjective "didactic" means instructional, educational, informative. Additionally, "provisional" means temporary, intended only for a short time; "amenable" means cooperative, agreeable; "distended" means bloated, swollen due to pressure; "recondite" means (of knowledge) arcane and privileged, known by only a few.

The adjective "benighted" means ignorant of. Additionally, "sagacious" means wise, possessing sagacity; "furtive" means (of a look) secretive, clandestine; "comely" means attractive; "fulsome" means excessively flattering, fawning, unctuous.

The adjective "esoteric" means understood by only a small number of people, arcane and privileged knowledge. The correct answer is therefore "arcane." Additionally, "ingenuous" means naive, easily misled by others; "truculent" means aggressive, quick to anger, eager to fight; "torpid" means inactive, sluggish, lacking energy; "pervasive" means spread throughout.

"Incognito" is an adjective meaning having one's identity concealed. "Disguised" means having altered one's appearance to hide one's identity. "Blatant" means obvious and done openly, "muted" means quiet and soft, "solitary" means isolated or done alone, and "perilous" means full or danger or risk.

Bleak means lacking vegetation or decoration, or bare. It can also mean not hopeful.