Persisting, Plucky, Potent, Powerful, Puissant, Remaining, Resistant, Robust, Rude, Rugged, Sinewy, Soldierly, Sound, Stable, Stalwart, Staying, Steadfast, Steely, Stiff, Stout, Strapping, Stringy, Strong, Stubborn, Sturdy, Tenacious, Tough, Untiring, Valiant, Vigorous, Vital, Wiry, Abiding, Aged, Ancient, Antique, Beefy, Bold, Bouncing, Brave, Chewy, Chivalric, Chivalrous, Chronic, Cohesive, Constant, Continuing, Courageous, Daring, Deciduous, Doughty, Durable, Enduring, Ephemeral, Evergreen, Fearless, Fibrous, Fit, Flush, Forceful, Forcible, Gallant, Gutsy, Hale, Hard, Healthy, Hearty, Hefty, Heroic, Husky, Immutable, Intrepid, Inveterate, Knightly, Lasting, Leathery, Lusty, Macrobiotic, Manly, Mighty, Nervy, Obstinate, Perennial, Permanent, Perpetual, Persistent