Firm

Definitions: (1) showing positive determination; resolute; steady; (2) full of or indicating vigorous strength; fixed; stable; (3) unchanging; constant <a firm unshakable faith>

Synonyms: robust, rugged, staunch, steadfast, sturdy, tenacious, unfaltering, unyielding

Balancing Quality: soft

Symbols: 1) the leg; 2) the column