Synonyms to unheard of

able, beguiling, bewildering, breakaway, different, enigmatic, exceptional, extraordinary, fabulous, fantastic, fascinating, ignotus, incalculable, incognizable, incomprehensible, inconceivable, incredible, inglorious, little known, marvelous, miraculous, mysterious, nameless, no credit to, novel, obscure, offbeat, original, outlandish, passing strange, phenomenal, prodigious, puzzling, rare, recherche, remarkable, renownless, sealed, sensational, strange, striking, stupendous, sui generis, unapparent, unapprehended, unascertained, unbeknown, uncelebrated, uncharted, unclassified, uncommon, uncustomary, undisclosed, undiscoverable, undiscovered, undistinguished, undivulged, undreamed-of, unexpected, unexplained, unexplored, unexposed, unfamed, unfamiliar, unfathomed, unglorified, unheard, unhonored, unidentified, unimaginable, uninvestigated, unique, unknowable, unknown, unnotable, unnoted, unnoticed, unordinary, unperceived, unplumbed, unpopular, unprecedented, unremarked, unrenowned, unrevealed, unsung, unsuspected, unthought-of, untouched, unusual, unwonted, virgin, wonderful, wondrous