Gul.

Gul. is a clerk's shortening of the given name William. Busy writers cut common first names down to a few letters, often raising the last letters above the line, and the habit runs through deeds, wills, tax lists and census pages.

Gul. comes from Gulielmus, the Latin form of William, and appears in records written in Latin, such as church registers, university lists and older legal papers. English-language records use Wm. instead, so the two forms can name the same man in different documents.