- lucia di lammermoor,
- lucifer match,
Origin of lucid
Word Origin for lucid
1590s, "bright, shining," from Latin lucidus "light, bright, clear," figuratively "perspicuous, lucid, clear," from lucere "to shine," from lux (genitive lucis) "light," from PIE root *leuk- "to shine, be bright" (see light (n.)). Sense of "easy to understand" first recorded 1786. Lucid interval "period of calm or temporary sanity" (1580s) is from Medieval Latin lucida intervalla (plural), which was common in medieval English legal documents (cf. non est compos mentis, sed gaudet lucidis intervallis). Related: Lucidly; lucidness (1640s).
1650s, "brightness," from French lucidité, from Late Latin luciditas, from lucidus (see lucid). Meaning "intellectual clarity" attested by 1851.