Where does “lunatical” come from?
lunatical (English) comes from English lunatic, from Middle English lunatik, from Old French lunatique, from Latin lūnāticus, from Latin lūna, from Old Latin losna, from Proto-Italic louksnā, from Proto-Indo-European lówksneh₂ — bright; to shine; to see.
lunatical (English): Lunatic
Ancestry of “lunatical”, step by step