limpid

Limpid describes something clear and transparent, especially water, and can also suggest brightness. English took the word from French limpide, which was a learned borrowing from Latin limpidus, meaning “clear, bright, transparent”; in Late Latin it could also mean “clean.”

The deeper origin of Latin limpidus is uncertain. One traditional proposal connects it with the Proto-Indo-European root *leh₂p- “to shine,” alongside words for lightning, flame, and light. Other explanations link it with Latin limpor, “clear liquid,” or lympha, “clear river water”; another derives it from a proposed form meaning “to be liquid.”