lucus a non lucendo
lu·cus a non lu·cen·do
ˈlükəˌsā¦nänlüˈsenˌdō
: an illogical explanation or absurd derivation : non sequitur
the whole discussion may seem a lucus a non lucendo for all the light it throws upon the effect of the classics on mediaeval literature
H. O. Taylor
H. O. Taylor
Word History
Etymology
New Latin, a grove from not being light; from the practice ascribed to ancient Roman etymologists of deriving words from their semantic opposites, as lucus ("grove") from lucēre ("to shine, be light") because a grove is not light