(b.) Ardor inspired by passion or enthusiasm.

activity alacrity animal spirits animation anxiety anxiousness appetite ardor avidity avidness breathless impatience brio briskness capersomeness cheerful readiness coltishness dash eagerness enthusiasm esprit exuberance forwardness friskiness frolicsomeness gaiety gamesomeness gayness glow gust gusto heartiness impatience impetuosity impetus joie de vivre keen desire keenness life liveliness lustiness mettle oomph perkiness pertness piss and vinegar playfulness promptness quickness readiness robustness rollicksomeness rompishness skittishness spirit spiritedness spirits sportiveness sprightliness verve vigor vim vitality vivacity warmth zest zestfulness zing zip