The story
From methyl + phosphon(ic) + -o- + fluoridate.
Etymology from Wiktionary, CC BY-SA 4.0.
methylphosphonofluoridate
Today it means: Any of a class of highly toxic organophosphorus compounds characterized by the methylphosphonofluoridate chemical structure, including sarin and soman. They are potent cholinesterase inhibitors, often used as chemical weapons. Full definition →