Matt.

Matt. is a clerk's shortening of the given name Matthew. 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.

Matthias, a different name, was shortened as Math., so watch the letters after the a. Matt. is also the usual short form for the Gospel of Matthew. A single extra stroke can change which name an index reports.