Synonyms and related words :
activity, animation, ardor, briskness, dash, elan, enthusiasm, esprit, glow, gusto, impetuosity, impetus, joie de vivre, life, liveliness, lustiness, mettle, oomph, perkiness, pertness, robustness, spirit, spiritedness, verve, vim, vivacity, warmth, zest, zestfulness, zing