lucus a non lucendo

The story

1. Latin · borrowed fromlūcus ā nōn lūcendō
2. English todaylucus a non lucendo

From Latin lūcus ā nōn lūcendō, literally "a grove from not shining", referring to Roman rhetorician Quintilian's assertion, in his Institutio Oratoria, that Latin lūcus (“grove”) derived from lūceō (“to shine”), because groves were dark places and did not shine.