Of an austere or hard nature; rugged.
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.
Complicated or tricky; complex, difficult.
As tough, hard, or inflexible as a piece of rock.
With strongly held beliefs and opinions, deep conviction.
With muscles developed and toned to a high degree, especially the muscles of the abdomen.
Having a very fully erect and stiff penis