cheeriness (noun) buoyancy/buoyance: lightness in spirit
Sinonime: changeable, deciduous, emigrating, ephemeral, evanescent,
flash, fleeting, flitting, fly-by-night,
flying, fugacious, fugitive, going by, impermanent,
insubstantial, migrating, momentary,
moving, passing,
provisional, short, short-lived, short-term,
temporal, transmigratory,
unstable, vacating,
volatileAntonime: enduring,
incessant, lasting, long-lasting, neverending, permanent,
persistent,
undying