ˈlükəˌsā|nänlüˈsenˌdō
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
: 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