Словарь

flightiness

Существительное

Пример: “Her apparent flightiness hid a sharp intelligence.”

Синонимы: frivolity, fickleness

Антонимы: seriousness, steadiness

arbitrary

Прилагательное

Пример: “The deadline felt arbitrary and poorly justified.”

capricious

/kəˈprɪʃəs/

Пример: “The weather here is capricious.”

Синонимы: arbitrary, whimsical, impulsive