• IPA: /ˈlaɪtnəs/

From Middle English lightnes, lightnesse, from Old English līhtnes, lȳhtnys, from Proto-West Germanic *liuhtinassī; equivalent to light + -ness.

lightness

1. (uncountable) the condition of being illuminated
2. (uncountable) the relative whiteness or transparency of a colour
3. (countable) The product of being illuminated.

• French: luminosité
• Portuguese: claridade, luminosidade
• Russian: освещённость

• French: clarté
• Spanish: luminosidad, claridad

From Middle English lightnes, lightnesse, from Old English *lēohtnes (compare Old English lēohtmōdnes, līhtingnes); equivalent to light + -ness.

lightness (uncountable)

1. The state of having little (or less) weight, or little force.
2. Agility of movement.
3. Freedom from worry.
4. Levity, frivolity; inconsistency.
   • 1624, Democritus Junior [pseudonym; Robert Burton], The Anatomy of Melancholy: […], 2nd edition, Oxford, Oxfordshire: […] John Lichfield and James Short, for Henry Cripps, →OCLC ↗:
     , New York 2001, p.75:

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

• French: légèreté
• Italian: leggerezza
• Russian: лёгкость
• Spanish: liviandad