Complicated or tricky; complex, difficult.
Of a part of the body, a tree, etc.: full of knots (knobs or swellings); gnarled, knobbly.
Of string or something stringlike: full of, or tied up, in knots.
Of an austere or hard nature; rugged.
overlapping; contorted; convoluted
Having two opposite leaves, each with one edge overlapping the nearest edge of the other.
Having a circle of several leaves or petals which overlap in that manner.