Divination by the interpretation of the appearance and behaviour of horses. Their neighing and stamping are particularly noted.
1713 Fabricii Bibliographia Antiquaria xii.Hippomantia ex hinnitu, fremitu, sudore..
1911 Encyc. of Religion & EthicsThere is also a trace of hippomancy in Persia. According to Herodotus (iii. 84-87), after Darius and six other Persian nobles had slain the pseudo-Smerdis, they agreed that he should be king whose horse should first neigh after sunrise, when they had mounted their steeds.
1973 L. Watson Supernature ix.Precoginition means "knowing in advance," and systems of knowing cover just about every possible source of variation. They include..hippomancy (based on the stamping of horses)... None of these need be taken seriously...