VIGOUR

n. vitality, resilience, strength, power, energy, forcefulness, force, stamina, endurance, mettle, mettlesomeness, pith, dynamism, spirit, liveliness, animation, verve, vivacity, exuberance, brio, briskness, zest, zealousness, enthusiasm, gusto, eagerness, Colloq spunk, pep, pizazz, vim, oomph, zing, get-up-and-go When attacked, they defended themselves with extraordinary vigour