FLIGHTINESS
flightiness, arbitrariness, whimsicality, whimsy, whimsey, capriciousness
(noun) the trait of acting unpredictably and more from whim or caprice than from reason or judgment; “I despair at the flightiness and whimsicality of my memory”
Source: WordNet® 3.1
Etymology
Noun
flightiness (countable and uncountable, plural flightinesses)
The quality of being flighty.
Source: Wiktionary
Flight"i*ness, n.
Definition: The state or quality of being flighty.
The flightness of her temper. Hawthorne.
Syn.
– Levity; giddiness; volatility; lightness; wildness; eccentricity.
See Levity.
Source: Webster’s Unabridged Dictionary 1913 Edition