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.
Divided or separated.
separate, disassociate, cause to come apart.
Cease to be together, break apart from the group.