THESAURUS
hardiness
assurance, audacity, brashness, bulldog courage, cohesiveness, decisiveness, durability, endurance, energy, force, fortitude, gameness, gaminess, grittiness, guts, gutsiness, haleness, hardihood, hardness, heartiness, infrangibility, intestinal fortitude, lastingness, leatherlikeness, longevity, lustihood, lustiness, mettlesomeness, might, mightiness, nerve, nerviness, obstinacy, pertinaciousness, pertinacity, pluckiness, potency, power, powerfulness, resistance, resoluteness, resolution, robustness, ropiness, ruggedness, spunkiness, stalwartness, stamina, staying power, sticking power, stiffness, stoutness, strength, strength of will, stringiness, stubbornness, sturdiness, tenaciousness, tenacity, toughness, unbreakability, unbreakableness, vigor, vigorousness, viscidity, vitality