Synonyms of little-known

1 Syllable
hard, dark, deep
2 Syllables
heavy, orphic, hidden, secret, cryptic, occult, profound, mystic
3 Syllables
concealed, involved, mystical, scholarly, abstruse, arcane, difficult, hermetic, unheard-of, pedantic
4 Syllables
unrenowned, academic, untraveled, acroamatic, esoteric, recondite, undetected, cabalistic, unexposed
5 Syllables
undiscovered