Roget's Thesaurus: Entry 571 (Obscurity)

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#571. Obscurity. -- N. obscurity &c. (unintelligibility) 519; involution; hard words; ambiguity &c. 520; unintelligibleness; vagueness &c. 475, inexactness &c. 495; what d'ye call 'em &c. (neologism) 563[obs]; darkness of meaning.

Adj. obscure &c. n.; crabbed, involved, confused.