lightness

noun

Etymology: From Middle English lightnes, lightnesse, from Old English *lēohtnes (“lightness”) (compare Old English lēohtmōdnes (“lightness”, literally “light-moodedness”), līhtingnes (“lightness, alleviation”)); equivalent to light (“not heavy”, adjective) + -ness (suffix forming nouns). Cognate with Middle Low German luchtnisse, lüchtnisse (“lightness, frivolity, joyfulness”).

1. The state of having little (or less) weight, or little force.

   “The unique chassis design is largely the secret of the lightness of the locomotive.”

2. Agility of movement.
3. Freedom from worry.

   “In the lightness of my heart I sang catches of songs as my horse gayly bore me along the well-remembered road.”

4. Levity, frivolity; inconsistency.

   “Seneca […] accounts it a filthy lightness in men, every day to lay new foundations of their life, but who doth otherwise?”

   “And if the sudden and unannounced arrival of Miss Melhuish at "The Turrets" contained any element of surprise for him, his habitual imperturbability enabled him to pass it off with disarming lightness.”