acquiescence, activity, agreeability, agreeableness, alacrity, amenability, amusement, animation, ardency, ardor, avidity, brio, briskness, bug, calenture, cathexis, cheerful consent, compliance, concern, concernment, consent, cooperativeness, craze, crazy fancy, curiosity, devotedness, devotion, diversion, docility, eagerness, earnest, earnestness, ebullience, elan, enthusiasticalness, excitement, exuberance, fad, fanaticism, fascination, favorable disposition, favorableness, fervency, fervor, fieriness, fire, forwardness, furor, furore, gameness, glow, goodwill, gusto, hobby, hurrah, impassionedness, impetuosity, impetus, infatuation, interest, joie de vivre, keenness, life, liveliness, lustiness, mania, manic-depressive psychosis, matter of interest, mettle, passion, pastime, perkiness, pertness, pliability, pliancy, promptness, rage, readiness, receptive mood, receptiveness, receptivity, relish, responsiveness, right mood, robustness, special interest, spirit, spiritedness, tractability, ungrudgingness, unloathness, unreluctance, vehemence, vivacity, warmth, willing ear, willing heart, willingness, zeal, zealousness, zest, zestfulness, zing