a baffling problem.
a knobbed stick.
a knotty problem.
a mass of knotted string.
a problematic situation at home.
Byzantine methods for holding on to his chairmanship.
convoluted legal language.
convoluted reasoning.
gnarled and knotted hands.
got his way by labyrinthine maneuvering.
I faced the knotty problem of what to have for breakfast.
Oh, what a tangled web we weave.
snarled thread.
the Byzantine tax structure.
the plot was too involved.
tortuous legal procedures.
tortuous negotiations lasting for months.