Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

ignorance, ignorance crasse [Fr.]; unfamiliarity, unacquaintance†; unconsciousness &c adj.; darkness, blindness; incomprehension, inexperience, simplicity. unknown quantities, x, y, z. sealed book, terra incognita, virgin soil, unexplored ground; dark ages. [Imperfect knowledge] smattering, sciolism†, glimmering, dilettantism; bewilderment &c (uncertainty) 475; incapacity. [Affectation of knowledge] pedantry; charlatanry, charlatism†; Philister†, Philistine. V. be ignorant &c adj.; not know &c 490; know not, know not what, know nothing of; have no idea, have no notion, have no conception; not have the remotest idea; not know chalk from cheese. ignore, be blind to; keep in ignorance &c (conceal) 528. see through a glass darkly; have a film over the eyes, have a glimmering &c n.; wonder whether; not know what to make of &c (unintelligibility) 519; not pretend to take upon, not take upon one self to say. Adj. ignorant; nescient; unknowing, unaware, unacquainted, unapprised, unapprized†, unwitting, unweeting†, unconscious; witless, weetless†; a stranger to; unconversant†. uninformed, uncultivated, unversed, uninstructed, untaught, uninitiated, untutored, unschooled, misguided, unenlightened; Philistine; behind the age. shallow, superficial, green, rude, empty, half-learned, illiterate; unread, uninformed, uneducated, unlearned, unlettered, unbookish; empty-headed, dizzy, wooly-headed; pedantic; in the dark; benighted, belated; blinded, blindfolded; hoodwinked; misinformed; au bout de son latin, at the end of his tether, at fault; at sea &c (uncertain) 475; caught tripping. unknown, unapprehended, unexplained, unascertained, uninvestigated†, unexplored, unheard of, not perceived; concealed &c 528; novel. Adv. ignorantly &c adj.; unawares; for anything, for aught one knows; not that one knows. Int. God knows, Heaven knows, the Lord knows, who knows, nobody knows. Phr. ignorance never settles a question [Disraeli]; quantum animis erroris inest! [Lat.] [Ovid]; small Latin and less Greek [B. Jonson]; that unlettered small-knowing soul [Love's Labor's Lost]; there is no darkness but ignorance [Twelfth Night].