The four Farthings were four of the five (later six) divisions of the Shire. They were known simply as Northfarthing, Westfarthing, Southfarthing and Eastfarthing. The Westron word was tharni, the Sindarin word (presumably) canath.
Farthings were further divided into folklands, that bore the names of the land's leading family, such as Tookland of the Westfarthing, named after the Took Family; although many other families had migrated to other regions by the late Third Age.
The four Farthings of the Shire were based on the three traditional Ridings (from the Old English thridings) of Yorkshire, which were formerly used as administrative divisions of the county (North Riding, West Riding and East Riding).
- J.R.R. Tolkien, The Lord of the Rings, "Prologue", "Of the Ordering of the Shire"
- J.R.R. Tolkien, The Lord of the Rings, The Return of the King
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Peoples of Middle-earth, "II. The Appendix on Languages", §41
- J.R.R. Tolkien, "Nomenclature of The Lord of the Rings" in Wayne G. Hammond and Christina Scull (eds), The Lord of the Rings: A Reader's Companion, p. 770 (see also p. 32)
- Riding (division) at Wikipedia