An ancient Roman rite celebrated at various times of the growing season, at which animals were led around fields before being sacrificed as an act of lustration.
Both public and private rituals might be held; private ones by landowners outside Rome, and a public ritual for those holding land within Rome itself. This latter is sometimes incorrectly connected with the May festival of the fratres arvales, a group of twelve priests worshipping the Dea Dia, a fertility goddess sometimes identified with Ceres.
Early 17th century; earliest use found in Thomas Coryate (?1577–1617), traveller and writer. From classical Latin ambarvālia, denoting a fertility ritual (attested in an 8th-cent. epitome of a 2nd-cent. grammarian), use as noun of neuter plural of ambarvālis going around the fields from amb- round, about + arvum ploughed field, ploughed land, use as noun of neuter of arvus ploughed, cultivated + -ālis.