knotty

adjective

1. 1

   tangled in knots or snarls

   a mass of knotted string

   snarled thread

2. 2

   making great mental demands; hard to comprehend or solve or believe

   a baffling problem

   I faced the knotty problem of what to have for breakfast

3. 3

   highly complex or intricate and occasionally devious

   the Byzantine tax structure

   Byzantine methods for holding on to his chairmanship

4. 4

   used of old persons or old trees; covered with knobs or knots

   gnarled and knotted hands

   a knobbed stick