CHILDISHNESS
n.Triflingness, puerility, the state or qualities of a child, in reference to manners. But in reference to the mind, simplicity, harmlessness, weakness of intellect.
CHILDISHNESS Child "ish *ness, n.
childishness
ch í ld ish ness 名詞 U ⦅けなして ⦆幼稚さ, 子供っぽさ .