peradventure (pur-ad-VEN-chur) adverb Maybe; possibly. noun Uncertainty; doubt.
[From Middle English per aventure, via French, from Latin per- (through) + adventurus, future participle of advenire (to arrive).]
"[Philip Coyle, former director of operational test and evaluation at the Pentagon] reckons America's chances of shooting down an enemy missile next year, if peradventure it needed to, are 'practically zero'."
-- Warding Off Missiles; The Economist (London, UK); Dec 6, 2003.