"brightness, luster, luminosity," 1650s, from lucent + abstract noun suffix -cy. Lucence is from late 15c.
Entries linking to lucency
lucent adj.
mid-15c., "shining, bright, luminous," from Latin lucentem (nominative lucens), present participle of lucere "to shine, glow, be bright," from PIE root *leuk- "light, brightness." Meaning "translucent, clear" is from 1820. Related: Lucently.
-cy
abstract noun suffix of quality or rank, from Latin -cia, -tia, from Greek -kia, -tia, from abstract ending -ia (see -ia) + stem ending -c- or -t-. The native correspondents are -ship, -hood.