Billy

Billy is a traditional English nickname for William, a name built from Germanic elements meaning “will” or “desire” and “helmet” or “protection.” “Resolute protection” summarizes those elements. Billy has also become a full first name, allowing families to keep the familiar, affectionate form rather than registering a longer William.

Bill is an even shorter everyday possibility. Billie is a closely related spelling and is particularly familiar for girls, although Billy itself has also been used for girls. The name’s approachable sound contrasts with the formality of William without losing the family connection. When honoring a relative, choosing Billy can preserve the name they were actually called rather than the version written on official documents.