1. (superl.) Full of knots; knotted; having many knots; as, knotty timber; a knotty rope.

2. (superl.) Hard; rugged; as, a knotty head.

3. (superl.) Difficult; intricate; perplexed.

Byzantine Herculean abstruse arduous beyond one brutal burled complex complicated crabbed cramp critical daedal delicate demanding difficile difficult effortful elaborate exacting formidable garbled gnarled gnarly gordian hairy hard hard to understand hard-earned hard-fought intricate involved jawbreaking jumbled knobbed knobbly knobby knoblike knotted knurled knurly laborious labyrinthine lumpy mean no picnic nodal noded nodiform nodose nodular nodulated noduled not easy nubbled nubbly nubby obfuscated obscure obscured operose overtechnical perplexed rigorous rough rugged scrambled set with thorns severe sophisticated spiny steep sticky strenuous studded terrible thorny ticklish toilsome torose tough tricky tubercular tuberculous tuberose tuberous uphill wicked