From Wiki - I guess cottar / cotter is just another term for crofter / smallholder, pre 1886.
Cotter,
cottier,
cottar,
Kosatter or
Kötter is the
German or
Scots term for a
peasant farmer (formerly in the
Scottish highlands for example). Cotters occupied cottages and cultivated small plots of land. The word
cotter is often employed to translate the cotarius of
Domesday Book, a class whose exact status has been the subject of some discussion, and is still a matter of doubt. According to Domesday, the cotarii were comparatively few, numbering less than seven thousand, and were scattered unevenly throughout
England, being principally in the southern counties; they were occupied either in cultivating a small plot of land, or in working on the holdings of the
villani. Like the villani, among whom they were frequently classed, their economic condition may be described as free in relation to every one except their lord.
A cottar or cottier is also a term for a tenant renting land from a farmer or landlord.
Highland Cotters (including on the islands, such as Mull) were impacted by the Industrial Revolution, as landowners realized they could make more money from sheep than crops. The landowners raised rents to unaffordable prices, or forcibly evicted entire villages, leading to mass exodus and an influx of former cotters into industrial centers, such as a burgeoning Glasgow.