What's the difference between i.e. and e.g.?
late 13c., perhaps via Anglo-French sodein, from Old French subdain "immediate, sudden," from Vulgar Latin *subitanus, variant of Latin subitaneus "sudden," from subitus "come or go up stealthily," from sub "up to" + ire "come, go." Phrase all of a sudden first attested 1680s, earlier of a sudayn (1590s), upon the soden (1550s). Sudden death, tie-breakers in sports, first recorded 1927; earlier in reference to coin tosses (1834).