knotty
Concise Oxford English Dictionary © 2008 Oxford University Press:
knotty/ˈnɒti/
▶adjective (knottier, knottiest)
- 1 full of knots.
- 2 extremely difficult or intricate.
– derivatives
knottily adverb,
knottiness noun.
knottily adverb,
knottiness noun.
'knotty' also found in these Oxford entries:

