- difficult [adj1] hard on someone; hard to do ambitious, arduous, backbreaker*, bothersome, burdensome, challenging, crucial, demanding, difficile, easier said than done*, effortful, exacting, formidable, galling, Gargantuan*, hardwon, heavy, Herculean*, immense, intricate, irritating, labored, laborious, no picnic*, not easy, onerous, operose, painful, problem, problematic, prohibitive, rigid, severe, stiff, strenuous, titanic, toilsome, tough, troublesome, trying, unyielding, uphill, upstream, wearisome; concept 538 —Ant. calm, easy, free, manageable, plain, simple, uncomplicated difficult [adj2] complicated; hard to comprehend abstract, abstruse, baffling, bewildering, complex, confounding, confusing, dark, deep, delicate, enigmatic, enigmatical, entangled, esoteric, formidable, hard to explain, hard to solve, hidden, inexplicable, intricate, involved, knotty, labyrinthine, loose, meandering, mysterious, mystical, mystifying, nice, obscure, obstinate, paradoxical, perplexing, problematical, profound, puzzling, rambling, subtle, tangled, thorny, ticklish, troublesome, unclear, unfathomable, unintelligible, vexing; concept 529 —Ant. easy, simple, straightforward, uncomplicated difficult [adj3] unmanageable socially argumentative, bearish, boorish, dark, demanding, fastidious, finicky, fractious, fussy, grim, hard to please, impolite, intractable, irritable, oafish, obstreperous, perverse, picky, refractory, rigid, rude, tiresome, tough, troublesome, trying, unaccommodating, unamenable; concepts 404,542,555 —Ant. calm, friendly, sociable
New thesaurus. 2014.