acre

Acre, the unit of land measurement, comes down to us from the Old English æcer, which inherited it from a common Germanic root. The word has cognates in other Indo-European languages too, like the Latin ager (which gives us the agri- in agriculture), the Greek ἀγρός (field), and the Sanskrit ajra (plain, open country). The modern spelling is influenced by the Norman French version of the word.

An example of Old English use of the word can be found in Ælfric of Eynsham’s Colloquy, a dialogue between a teacher and student used in teaching Latin. Beyond the linguistic value of the text, the Colloquy is useful for the view it gives into everyday life in early medieval England:

Eala, leof hlaford, þearle ic deorfe. Ic ga ut on dægræd þywende oxon to felda, & iugie hig to syl; nys hit swa stearc winter þæt ic durre lutian æt ham for ege hlafordes mines, ac geiukodan oxan, & gefæstnodon sceare & cultre mit þære syl, ælce dæg ic sceal erian fulne æcer oþþe mare.

Oh, dear master, I work too hard. I go out at dawn driving the oxen to the fields & yoke them to the plow; it is not so harsh a winter that I dare lie at home for fear of my master, but with yoked oxen, & with the plow fastened to share and coulter, each day I have to plow an entire acre or more.

A share and coulter are the blades of a plow. The Latin word in the Colloquy corresponding to æcer is ager.

Originally, an acre was defined as an area that could be plowed by a team of oxen in a day. Later, was more precisely defined in law as 1/640 of a square mile, that is 4,840 square yards or 0.405 hectares. It is still a statute measure in the United States, but its use in other anglophone countries is now customary rather than legal. The plural acres is also used to refer to an expanse of land of indeterminate size; this plural usage dates from the mid eighteenth century.

Sources:

Ælfric. Ælfric’s Colloquy (1939). G. N. Garmonsway, ed. Exeter Medieval Texts & Studies. Exeter: U of Exeter Press, 1991, lines 23–27, 20. London, British Library, MS Cotton Tiberius A.iii, fols. 60v–64v.

Dictionary of Old English: A to Le, 2024, s.v. æcer, n.

Middle English Dictionary, 2019, s.v. aker, n.(1).

Oxford English Dictionary, third edition, December 2011, s.v. acre, n.

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