The ”Lorimer” surname has its origins in the early Middle Ages (or Medieval Age) and is an occupation name. The first bearers of the name were so-called because it reflected their trade: a “Lorimier” was a metal craftsman who made spurs, stirrups, bits and other such horse-related metal-ware.
The Norman conquest of England, by William the Conqueror, brought with it a French-speaking regime to the British Isles. William I of England rewarded his loyal supporters and warriors with land and titles and it is during this period that we see a large influx of French words and names in the English language.
The Old French word “Lorimier” or “Lorinier” was itself derived from the Latin, “Lorimarius” and early usage of the name has been recorded in that form with a Hugh Lorimarius being granted lands at Perth by King William I (The Lion) who ruled Scotland from 1165 to 1214. The same lands are later recorded as being sold by a descendant of Hugh, called Matthew Lorimer.
The spelling of surnames was not standardised during early usage which has resulted in numerous variations, however the origins would still be the same for Lorrimer, Lorrimar, Lorimar, L’armour, Lorrymer, Larimore and many other variant spellings.
The famous Domesday Book, compiled in 1086, formed a census of most of England and Wales as a means of determining how much tax could be wrung from the lands William I had conquered. One individual, Jocelyn The Lorimer, is shown to hold large areas of land, in what is now East Anglia, after the Conquest.
Source: [http://lorimer.biz]