Short form of William, from Germanic 'wil' (will, desire) and 'helm' (helmet, protection).
Bill began its life as a medieval English nickname for William, itself derived from the Old High German *Willahelm* — a compound of *willo* (will, desire) and *helm* (helmet, protection), together conveying something like "resolute protector" or "determined guardian." William arrived in England with the Norman Conquest of 1066, carried by the Conqueror himself, and promptly became one of the most common masculine names in the English-speaking world. Bill emerged as a rhyming alteration of Will — a common medieval naming trick, much as Bob derived from Rob and Ned from Ed — and settled into the vernacular as the plainspoken, democratic face of the royal name.
, the co-founder of Alcoholics Anonymous, whose anonymity became its own kind of fame; Bill Monroe, the father of bluegrass; Bill Evans, who made jazz piano sound like thought itself. William Shakespeare was also often called Will, keeping the full name in loftier company, while Bill remained the name of the working world — of factories, bars, baseball diamonds, and small-town diners. By the late twentieth century, Bill had acquired the comforting weight of reliability — a name that makes no pretensions and keeps its promises.
Its recent decline in new birth registrations has given it a pleasingly vintage quality; today a baby Bill carries the slight surprise of an old name genuinely reappearing, not ironically recycled. It is one of the few names that manages to be simultaneously ordinary and completely distinctive.