Definition from Wiktionary, the free dictionary
From Middle English toname, tonome, from Old English tōnama (“surname”), equivalent to to- + name. Cognate with West Frisian tanamme, Dutch toenaam, Middle Low German toname, German Zuname, Danish tilnavn, Swedish tillnamn.
- A name added to another name; surname.
- A name in addition to the Christian name and surname of an individual, to distinguish him or her from others of the same name and usually indicating descent, place of residence, or some personal quality or attribute. Such to-names are often employed where the same families continually intermarry, and where consequently the same name is common to many individuals.