Synonyms to in the wings

abstruse, Herculean, abstract, arcane, arduous, beclouded, blind, brutal, buried, civilized, close, clouded, complex, complicated, concealed, covered, covert, critical, cultivated, cultured, deep, delicate, demanding, difficile, difficult, eclipsed, educated, encyclopedic, erudite, esoteric, exacting, formidable, hairy, hard, hard-earned, hard-fought, heavy, hermetic, hid, hidden, hypothetical, ideal, in a cloud, in a fog, in eclipse, in purdah, incommunicado, intricate, jawbreaking, knotted, knotty, laborious, latent, learned, lettered, literate, mean, mysterious, no picnic, not easy, obfuscated, obscure, obscured, occult, operose, pansophic, polyhistoric, polymath, polymathic, profound, recondite, rigorous, rough, rugged, scholarly, scholastic, secluded, secluse, secret, sequestered, set with thorns, severe, spiny, steep, strenuous, studious, thorny, ticklish, toilsome, tough, transcendental, tricky, under an eclipse, under cover, under house arrest, under wraps, underground, unknown, uphill, wicked, wise, wrapped in clouds, furtive, artful, back-door, backstairs, calculating, chiseling, clandestine,