Thom
A short form of Thomas, used as a surname from a forebear’s given name.
The #6,185 most common surname in the United States (2010 Census) — about 1 in every 55,821 Americans shares it.
Etymology
Thom is a shortened form of the medieval personal name Thomas. The name Thomas ultimately comes through Greek and Latin from an Aramaic/Hebrew name meaning "twin." In surname use, Thom usually began as an identifying reference to "Thomas's son" or "the family of Thom," especially in records where short pet forms were common.
History
The form appears in medieval English records as both a given-name nickname and a hereditary surname. It survives as a comparatively uncommon surname, and is closely related to larger surname families such as Thomas, Thomson, and Thompson. In some areas, especially in the north of England and Scotland, short forms like Thom were natural building blocks for later surnames.
Origin
Regions
Variant spellings
Fun fact
Old dictionaries often glossed Thomas as meaning "twin," and Thom is one of the simplest surname forms built from that very common medieval name.
From the historical record
“Thistle- Wood [O.E. J>wte/ -(- vmdu\ THOM, a dim. of Thomas, q.v. Robert fil. Thome.— Hund. Rolls. THOMAS (A.-Fr.-Lat.-Gr.-Heb.) Twin [Lat. Thomas, Gr. Thomas {Qaims) ', Heb. Tomi\ Witodllce Thomas, 4n of J>am twelfum, l>e is gecweden Z)idimus [Gr. SlSv/ios,”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)